“Solanum dulcamarum Africanum, foliis crassis hirsutis”, cultivated in England, at James Sherard’s garden in Eltham (Hortus Elthamensis) in 1726, originally from South Africa, Cape of Good Hope, Anonymous s.n. (lectotype, designated here: Dillenius, Hortus Elthamensis 365, t. 273. 1732). “Solanum Afric., frutescens, foliis angulatis, crassis et hirsutis, fl. caerulei. H. Eltham 1726” (epitype, designated here: OXF [Dill-HE 273-352, sheet 1]).

Scrambling vine to shrublet, 0.5–2 m. Stems strongly 4-winged, the wings less prominent on older stems, glabrous, minutely papillate or sparsely to moderately pubescent with antrorse simple uniseriate trichomes to 0.5 mm long, these arising from a multicellular base and deciduous, leaving the base and the stems apparently toothed; new growth glabrous or minutely papillate especially on leaf margins. Bark of older stems pale yellowish brown. Sympodial units plurifoliate, the leaves not geminate, evenly distributed along branches. Leaves simple or shallowly lobed, (1)2–5.2 cm long, (0.6)0.9–2.5 cm wide, elliptic to narrowly elliptic, thick and fleshy, both surfaces glabrous; major veins 3–4 pairs, not easily visible, the finer venation not visible; base cuneate and decurrent onto the stem; margins entire or with up to 3 shallow lobes, pubescent with antrorse uniseriate trichomes from broad bases like those of the stems giving an appearance of minute teeth, revolute in herbarium specimens; apex acute to slightly rounded-acute; petiole indistinct, if discernible to 1 cm with a narrow wing of leaf tissue along entire length. Inflorescences terminal, 1–10 cm long, 2–4(6) times branched, with 10–30 flowers, glabrous or with scattered bulbous-based simple uniseriate trichomes < 0.5 mm long; peduncle 0.5–2.5 cm long, sometimes purple as are the pedicels; pedicels 0.8–1.2 cm long, ca. 0.5 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, nodding or spreading at anthesis, glabrous or sparsely pubescent with simple uniseriate trichomes < 0.5 mm long, articulated at or near the base, leaving a tiny raised peg ca. 0.5 mm in the inflorescence axis; pedicel scars irregularly spaced in clumps. Buds globose becoming ellipsoid before anthesis, strongly exserted from the calyx tube long before anthesis. Flowers 5-merous, apparently all perfect. Calyx tube 1–1.5 mm long, openly cup-shaped, the lobes 1–1.5 mm long, deltate, fleshy and sometimes dark purple, the margins thickened in dry material, with a tuft of simple uniseriate trchomes at the tip, these ca. 0.25 mm long, yellowish when dry. Corolla 1.2–1.6 cm in diameter, violet-blue, stellate, lobed ¾ of the way to the base, the lobes 6–6.5 mm long, 2.5–4 mm wide, spreading at anthesis, glabrous adaxially, densely pubescent or papillate abaxially on the tips and margins, the trichomes < 0.2 mm long. Stamens equal; filament tube absent; free portion of the filaments 1–1.5 mm long, minutely papillate at the base adaxially; anthers 2.5–3 mm long, 1–1.5 mm wide, ellipsoid, loosely connivent, bright yellow, smooth abaxially, poricidal at the tips, the pores lengthening to slits with age, the tips paler and thickened in dry material. Ovary globose, glabrous; style 5.5–6.5 mm long, glabrous, apparently exserted from the bud before anthesis; stigma capitate, the surface minutely papillate. Fruit a globose to ellipsoid berry, 0.7–0.8 cm in diameter, purplish black when mature, juicy, the juice purple, the pericarp thin and shiny; fruiting pedicels 1.1–1.3 cm long, ca. 1 mm in diameter at the base, somewhat woody (?), nodding or spreading; fruiting calyx lobes slightly reflexed. Seeds 6–10 per berry, ca. 3 mm long, ca. 2.5 mm wide, flattened reniform with thickened margins, rusty brown, the surfaces minutely pitted, the testal cells pentagonal in outline.

Figure 3. 

Solanum africanum Mill. Lectotype of S. africanum “Solanum Afric., frutescens, foliis angulatis, crassis et hirsutis, fl. caerulei H. Eltham 1726” from Dillenius, Hortus Elthamensis 365, t. 273. 1732. Reproduced with permission of the Natural History Museum Library.

(Figure 4). Endemic to the coastal region of South Africa (most commonly collected in Eastern and Western Cape provinces, a few collections from North West, Gauteng and KwaZulu-Natal provinces).

Figure 4. 

Distribution of Solanum africanum Mill.

Dunes and strand habitats near the sea; 0–50 m elevation.

South Africa: dronkbessie (SANBI, http://www.ispotnature.org/species-dictionaries/sanbi/Solanum%20africanum).

(IUCN 2014). Least Concern (LC). EOO 62,716 km² (LC), AOO 36 km² (EN). Solanum africanum is widely distributed along the southern part of South Africa, and although the AOO calculated here indicates some conservation concern, this is in part due to the releatively low number of specimens we have examined. The species occurs in several protected areas, and is likely to be more common than our data suggest.

Solanum africanum was recognised by Linnaeus as part of his S. dulcamara L. It is superficially similar to that species, but differs in its ellipsoid, rather than tapering, anthers (see Knapp 2013), its purple berries and in its strongly angled stems (Fig. 1A). It is sympatric with and could be confused with S. guineense, but the branched inflorescence with smaller flowers distinguish S. africanum. The fruits of S. guineense are orange when ripe. Leaf shape and pubescence vary a great deal throughout the range of S. africanum; plants from drier habitats near the sea appear to have fleshier leaves, but pubescence does not seem to be environmentally influenced. Juvenile leaves appear to have more deeply incised margins, but some flowering specimens also have incised leaves.

Miller (1768) coined the binomial S. africanum as a replacement at the species level for Linnaeus’ variety of S. dulcamara “β Solanum dulcamarum africanum, foliis crassis hirsutis” (Linnaeus 1753), correctly recognising its distinctness. The only flowering material either author cited was the illustration (Fig. 3) from Dillenius (1732), although it is clear that Miller grew the plant at Chelsea and knew it from live material, at least vegetatively. He states clearly its differences to S. dulcamara – “some who have supported this and our common nightshade to the be same, which is certainly a great mistake, for this sort will not live abroad [outside] through the winter in England in any situation, nor does it produce flowers here with any treatment, for there are plants in the Chelsea Physic Garden of several years old, which have been differently managed, and yet have never flowered.” None of the four sheets in the Sherard herbarium at OXF match the plate from Hortus Elthamensis (Dillenius 1732) exactly (as is often the case, see S. campechiense L., Knapp and Jarvis 1989); the plate seems to combine some elements from several of the sheets at OXF, or may have been drawn from live plants. Two are sterile branches, and two bear one flowering branch each in addition to a sterile branch with juvenile leaf morphology. The epitype we have selected is the sheet dated “H. Eltham 1726” with one branch whose inflorescence mostly closely matches that in the plate (Dill-HE 273-352, sheet 1) and that bears the date 1726.

Solanum quadrangulare, the name by which this plant was long known, was the name coined for this species by Carl Peter Thunberg, Linneaus’ pupil who collected extensively in South Africa. It refers to its quadrangular stems. We have selected the sheet in the herbarium of the Linnean Society of London (LINN 248.26) as the lectotype of this name; it has an annotation in Linneaus’ handwriting and a reference to Thunberg (“T 476/CBS”).

Solanum crassifolium was based on the same Dillenius (1732) illustration as S. africanum, and we consider the names homotypic.

Thunberg’s species S. bracteatum first appears to have been effectively published in 1818, in his Flora Capensis (Thunberg 1818). In that work he refers to “Act. Gor.” that is probably an earlier place of publication (in the entry for S. quadrangulare he refers to “Acta Gor. 1812”). This is a reference to the botanic gardens of Count Alexis de Razumovsky at Gorenki, just outside Moscow, whose director was Friedrich E.L. Fischer, who later went on to be director of the botanic gardens in St. Petersburg. We have been unable to find an 1812 publication attributable to the “Société Phytographique de Gorenki”, nor is S. bracteatum listed among the plants grown at Gorenki at that time (Fischer 1812). Fischer also edited the Mémoires de la Société Impériale des Naturalistes de Moscou, and in the preface to volume 5 (Fischer 1817) refers to the first four volumes of the Mémoires being consumed by flames, presumably during the Napoleonic sack of Moscow, and the fusion of the Gorenki society with that of Moscow (“Les Mémoires de la Société Impériale des Naturalistes de Moscou consistant en quatre volumes, avoient, à la catastrophe de 1812 les sort de tant d’autres objects d’être consumes par les flammes. Il m’a paru important de faire paroître aussitôt de possible les matériaux qui se sont depuis rassemblés et qui, apres la réunion de la Société phytogeographique de Gorenki à la nôtre, sont devenus si intéressans pour la botanique – et de recommencer l’impression d’un ouvrage brûlé….”). An article by Thunberg (1817) in the same volume of the Mémoires does not include S. bracteatum, nor any references to “Act. Gor.” It is possible (and seems to us probable) that the original Thunberg publication scheduled for publication in 1812 never appeared in print, and thus this name is effectively published only in the Flora Capensis of 1818 (Thunberg 1818). The 1812 publication may, however, turn up, and that then would be the correct date of publication of S. bracteatum. We have found no specimens or other original material for S. bracteatum. Thunberg (1818) distinguished S. bracteatum from S. quadrangulare by its bracteate, less-branched inflorescences, but the branched inflorescence and black fruit clearly indicate it is a synonym of S. africanum, rather than S. guineense.

Dunal (1852) described a variety of taxa at both the species and subspecies level that we consider synonymous with S. africanum. Solanum aggerum was described from a specimen collected at “Zitzikania” in 1839 held in “herb. Boiss.”; a specimen at MO with the locality “Goukania, Feb” is possibly an isotype. These all represent leaf shape and pubescence variants of S. africanum. We have been unable to trace any duplicate material of the two collecctions cited by Dammer (1906) in the protologue of S. quadrangulare var. glabrum (Rust 430, 484); these specimens were likely to have been destroyed in Berlin.

South Africa. Eastern Cape: Thornhill, 5 miles W, Dist. Port Elizabeth, 27 Apr 1947, Acocks 13666 (K); Bushman’s River Mouth, left hand bank from sea, Oct 1973, Arnold 594 (K); Baviaans Kloof, 3 Jun 1976, Bayliss 7484 (G); Port Elizabeth, near the Block House, 13 Dec 1813, Burchell 4342 (K); Port Elizabeth, at Cape Recife, 24 Dec 1813, Burchell 4389 (K); Van Staden’s River, near the ford (Uitenhage Division), 9 Feb 1814, Burchell 4668 (K, LE); Kowie, Dist. Bathurst [Kowie River?], Aug 1929, Dyer 2010 (K); Slang River, Div. Humansdorp, Mar 1922, Fourcade 2178 (K); Kahoon River, near river mouth, Div. East London, 15 Apr 1900, Galpin 2690 (K); Alexandria forest, 28 Apr 1931, Galpin 10687 (BM,K); Uitenhage, 33°46’ S, 25°24’ W, Jan 1899, Haagner s.n. (K); Boknesstrand, Richmond, Dist. Alexandria, 20 May 1954, Johnson 930 (K); Port Elizabeth, 1894, Laidley & Co. 274 (G); Tzitzikama Park, Storm’s River mouth near beach, Dist. Humansdorp, 30 Jan 1966, Liebenberg 7861 (K); Sea View, 16 Mar 1931, Long 395 (K); Quora mouth, 25 Mar 1973, Strey 11187 (E, K); Klipdrift, Div. Humansdorp, May 1860, Thode A-2494 (K); Bathurst, Kowie W., May 1914, Tyson s.n. (G); Alexandria Forest Station, Dist. Alexandria, 26 Feb 1986, Wells 2780 (K); Uitenhage, Zeyher 75 (K). KwaZulu-Natal: Umzimkulo River, Drège s.n. (K); Uvongo Beach, Port Shepstone region, Apr 1968, Liebenberg 8120 (K); Illovo, lower Illovo [River], 4 May 1894, Medley Wood 6390 (BM, E, K); Umdloti, 23 Feb 1969, Ross 1991 (EA, K). North West: Zwartkopsrivier, in valley and surrounding hills from Villa Paul Mare to Uitenhaag, Ecklon & Zeyher s.n. (CAS). Western Cape: Riversdale, playas y dunas de Witsand, 20 Jan 2008, Aedo et al. 18685 (MA); Strandfontein, 19 Jun 1956, Baker 1001 (BM); Kynsna, 4 May 1963, Bayliss 1402 (G); Bilou River, Knysna District, Mar 1910, Fourcade 626 (K); Gordan’s Bay, 16 Apr 1914, Garside 484 (K); Grootbos Forest, Stanford, E of Hermanus, 2 Feb 1982, Hepper 7320 (K); Cape Agulhas, southernmost tip of Africa, 2 Feb 1982, Hepper 7321 (K); Bredasdorp de Hoop, edge of lake at south end of nature reserve, 3 Feb 1982, Hepper 7323 (K); Muizenberg, Diep River, prope Muizenberg, Mar 1899, MacOwan 1930 (BM, G, K); Cape of Good Hope, Nelson s.n. (BM); Strand, Stellenbosch Division, 26 Feb 1942, Parker 3652 (K); Mossel Bay, near Klas Meyer’s, Aug 1847, Prior s.n. (K); Strand, Hottentots Holland, Jan 1880, Rogers s.n. (K); False Bay, prope Muizenberg, 3 Apr 1892, Schlechter 640 (G); Muizenberg, by railway, 11 Mar 1896, Wolley-Dod 1018 (K); Walk Bay, near Capetown, Mar 1910, Worsdell s.n. (K).

Madagascar. Toliara: Forêt de Zombitsy (Sakaraha), aux confins des basins du Fiherenana et de L’Onilahy, forêt tropophile sur sables siliceux de l’Isalo, 26-29 March 1955, 600-850 m, H. Humbert, L. Bègue & R.P.R. Capuron 29654 (holotype: P [P00349299]; isotypes: K [K000414193], MO [MO-150886]).

Subshrub or shrub to canopy liana, of extremely variable height. Stems terete, finely dendritic pubescent at the tips, glabrescent. New growth unevenly pubescent, with densely branched dendritic to echinoid uniseriate trichomes ca. 0.2 mm long. Bark of older stems smooth, almost white to brown, glabrous. Sympodial units plurifoliate, the leaves not geminate, evenly distributed along young branches and clustered on short shoots on older plants. Leaves simple, 3-4.5 cm long, 1.2-2(3) cm wide, ovate to elliptic, rarely obovate, membranous to chartaceous, concolorous to weakly discolorous, both surfaces glabrous or pubescent with dendritic trichomes ca. 0.1 mm long; major veins 5–7 pairs, spreading at ca. 45° to the midvein and forming loops, the finer venation a prominent network of fine brown veins visible abaxially in herbarium specimens; base cuneate to truncate; margins entire or with up to 2 pairs of lobes in the lower half and with sinuses halfway to the midrib, the lobes rounded at the tips; apex acute to rounded; petiole 0.7–1.5 cm long, slender, densely dendritic-pubescent like young stems, glabrescent. Inflorescences terminal on short shoots, 2–5 cm long, unbranched or furcate, with 1–3 flowers, evenly dendritic-pubescent, the trichomes 0.1–0.2 mm long; peduncle absent or up to 2.5 cm long; pedicels ca. 1.5 cm long, apically dilated, ridged when dry, evenly dendritic-pubescent like the rachis, articulated 0–0.5 mm from base; pedicel scars irregularly spaced 1–5 mm apart, prominent. Buds ellipsoid, the corolla only just emerging from the calyx tube before anthesis, the tip of the bud shorter than the calyx lobes. Flowers 5-merous, apparently all perfect. Calyx tube 2–3 mm long, cup-shaped, the lobes 2–3 mm long, 1.5–2 mm wide at base, unevenly deltate, acute, evenly pubescent with dendritic trichomes like those of the rest of the inflorescence, with simple uniseriate trichomes up to 0.2 mm long on the margins. Corolla 1.2–2 cm in diameter, violet, stellate, lobed almost to base, the lobes 5–10 mm long, 2–3 mm wide, ovate to narrowly triangular, glabrous adaxially, sparsely pubescent abaxially, more densely pubescent at the tips with translucent, simple and/or dendritic trichomes. Stamens equal; filament tube ca. 1 mm long; free portion of the filaments 1–2 mm long, glabrous; anthers 3.5–4 mm long, ca. 1.5 mm wide, broadly oblong or ellipsoid, loosely connivent, smooth abaxially, poricidal at the tips, the pores much smaller than anther apices, ca. 0.4 mm in diameter, clearly delineated and not lengthening with age. Ovary conical, glabrous; style 7–8 mm long, protruding 2–3 mm beyond the anthers, curved, glabrous; stigma clavate, dark, the surface minutely papillose. Fruit an elongated ovoid berry, ca. 1.3 cm long, ca. 1 cm in diameter (immature?), apically pointed, the pericarp thin, glabrous; fruiting pedicels 1.5–3 cm long, ca. 0.8 mm diameter at base, pendent, ridged; fruiting calyx slightly accrescent, the lobes to ca. 5 m long, ca. 4 mm wide and forming a loose cup around the developing fruit. Seeds not known.

Figure 5. 

Solanum betroka D’Arcy & Rakot. A Flowering stem B Flowering stem with lobed leaf C Flower D Immature berry E Flower just before anthesis, showing elongate calyx lobes F Simple trichome G Dendritic trichome (Based on: A–D, F, GBosser 17370; ELeroy 3). Scale bar: A, B = 2 cm; C, E = 7 mm; D = 1 cm; F, G = 0.3 mm. Drawn by Lucy T. Smith.

(Figure 6). Endemic to Toliara province in southern Madagascar.

Figure 6. 

Distribution of Solanum betroka D’Arcy & Rakot.

Open dry forest and scrub on limestone or sand; 600–1100 m elevation.

None recorded.

(IUCN 2014). Least Concern (LC). EOO 62,716 km² (LC), AOO 36 km² (EN). Solanum betroka is confined to the arid southern part of Madagascar, with some disjunct populations to the north, giving the EOO indicating least concern. Given the paucity of collections of all of the Malagasy members of the ANS clade, and the widespread and continuing habitat alteration in Madagascar, we feel this species would merit conservation concern, but the AOO may also be indicative of collection deficit or bias.

Solanum betroka is a spindly shrub or liana endemic to southern Madagascar. It has small membranous lobed leaves with prominent finer venation clustered on the tips of branches, no more than 3 flowers per inflorescence, and no tufts of trichomes in the axils of the major leaf veins on leaf undersides (domatia). It is the only species of Solanum endemic to Madagascar not a member of the Leptostemonum clade to commonly exhibit lobed leaves (Fig. 5) on reproductive stems; lobed leaves in S. madagascariense occasionally occur but are rare.

Solanum betroka can be difficult to distinguish from the very similar and possibly closely related S. sambiranense and S. imamense. It differs from S. sambiranense by its ovate to elliptic (versus elliptic to obovate) leaves under 5 cm (versus over 5 cm) long, with cuneate to truncate (versus attenuate) bases, inflorescences with 1–3 (versus 3–10) flowers, and calyx lobes 2–3 mm (versus 4–6 mm) long. Solanum betroka bears a strong resemblance to S. sambiranense: both have a clearly visible brown fine venation network, membranous glabrescent leaves that dry greenish brown, and a similar habit. Typical representatives of the southern S. betroka and northern S. sambiranense are clearly distinct but specimens from the centre of Madagascar are more difficult to determine. Further sampling may prove that these two taxa are in fact conspecific. Solanum betroka can be distinguished from S. imamense by its inflorescences with 1–3 (versus 7–13) flowers, flowers under 2 cm (versus over 2 cm) in diameter, and anthers 3.5–5 mm (versus 4–5 mm) long.

Solanum betroka has also been confused with unarmed specimens of the spiny solanums S. batoides D’Arcy & Rakot. and S. erythracanthum Dunal; these can be distinguished easily based on pubescence and anther morphology. Solanum betroka has dendritic trichomes and ellipsoid anthers while S. batoides and S. erythracanthum have the stellate trichomes and long-tapered anthers typical of members of the Leptostemonum clade (Vorontsova et al. 2013; Vorontsova and Knapp 2016).

Solanum betroka occurs primarily in the unique arid southern ecoregion of Madagascar, with a few records further north in the somewhat wetter western ecoregion (Humbert 1955; Faramalala 1988, 1995). It is the only member of the African non-spiny clade restricted to such severely dry climate, although a few spiny Solanum species also occur in the area: Solanum batoides, S. bumeliifolium Dunal, S. croatii D’Arcy & R.C.Keating, and S. heinianum D’Arcy & R.C.Keating; the related S. imamense is partly sympatric with S. betroka in the wetter more northern parts of its distribution range. The habitat niche of S. betroka is significantly different from that of S. imamense and S. sambiranenese both of which occur in wetter habitats further north.. The type collection has smaller leaves with more lobes and denser indumentum than the majority of specimens, and does not exhibit the characteristic pronounced brown venation on dry leaves.

Madagascar. Toliara: Tulear-Ihosy km 44, 12 Nov 1967, Bernardi 11407 (G, P); environs de Betroka, Feb 1963, Bosser 17370 (K, MO, P, TAN); Ambovombe, 2 Feb 1926, Decary 3729[a] (MO, NY); Taolagnaro (F-Dauphin), Angavo, massif de l’Angavo á l’Est d’Antanimora, 16 Jul 1926, Decary 4443 (K, MO, P); Amboasary-Sud, Ampasimpolaka à l’est d’Ambovombe, 29 Jun 1931, Decary 9046 (MO, P); Bekily, Ampandrandava, 1943, Herb Jard Bot Tananarive 6083 (P); Zombitsy, Forêt de Zombitsy (Sakaraha) aux confins des bassins du Fiherenana et de l’Onilahy, Mar 1955, Humbert et al. 29627 (K, MO, NY, P); 57 km de Tulear, P.K. 888, 23 Oct 1966, Leroy 3 (P); Forêt de Zombitse [Zombitsy], 13 Apr 1961, Peltier & Peltier 3069 (P, TAN); Bekily, environs d’Ampandrandava (entre Bekily et Tsivory), Nov 1942, Seyrig 371 (MO, P).

South Africa. “In Guinea”, Anonymous s.n. (lectotype, designated by Wijnands 1983, pg. 193: LINN 246.4)

Lax scrambling many-stemmed shrub to 1 m tall, rhizomatous (?) with extensive underground root system (van Breda 4164). Stems erect or pendent, terete, glabrous to densely and finely pubescent with minute simple uniseriate gland-tipped trichomes, occasionally also with longer simple 4–5 celled uniseriate trichomes to 0.5 mm long; new growth densely glandular pubescent. Bark of older stems pale yellow-green or greenish brown. Sympodial units plurifoliate, the leaves not geminate, clustered on short shoots or less commonly evenly distributed along branches. Leaves simple, 1.5–6 cm long, 0.7–3.3 cm wide, ovate or more rarely elliptic, highly variable in size along single branches, apparently somewhat fleshy, both surfaces glabrous to densely and finely pubescent with gland-tipped simple uniseriate trichomes < 0.5 mm long and longer, eglandular simple uniseriate trichomes ca. 0.5 mm long, these denser on the veins abaxially, if the leaves glabrous then at least some gland-tipped trichomes found on margins and abaxial veins; major veins 4–5 pairs, not clearly visible; base truncate to cuneate, only slightly decurrent onto the petiole; margins entire or occasionally with a few shallow lobes, with at least some minute gland-tipped simple trichomes; apex bluntly acute; petioles 0.5–2 cm long, glabrous to densely and finely pubescent, pubescence in parallel with the stems, denser in adaxial groove. Inflorescences arising directly from short shoots that sometimes bear condensed scale-like leaves, with 1–3(5) flowers arising all from the same point on the stem, pubescent like the stems; peduncle absent; pedicels 1.2–2.5 cm long, ca. 1 mm in diameter at the base, ca. 1.1 mm in diameter at the apex, spreading at anthesis, glabrous or finely pubescent with minute simple uniseriate trichomes < 0.3 mm long, articulated at the base; pedicel scars closely spaced in what appears to be a fascicle. Buds ovoid, deeply included in the narrowly conical calyx tube, only halfway exserted just before anthesis. Flowers 5-merous, apparently all perfect. Calyx tube 2–4 mm long, narrowly conical, the lobes 1–2.5 mm long, narrowly triangular or somewhat spathulate, the apex rounded, pubescence like that of the pedicels and stems. Corolla 2–5 cm in diameter, 1–2.7 cm long, pale violet or purple-blue to white with a darker purple centre, stellate, lobed less than halfway to the base, the lobes 10–13 mm long, 5–6 mm wide, narrow and tongue-like with rounded, hooded tips, spreading at anthesis, sparsely pubescent along the lobe midvein adaxially, densely pubescent with minute simple papillae abaxially, these denser on the margins and tips. Stamens equal; filament tube very short, almost absent; free portion of the filaments 2–3.5 mm long, glabrous or sparsely pubescent at the base; anthers 5–5.5 mm long, 1.5–2.5 mm wide, ellipsoid, connivent or slightly spreading, bright yellow, smooth abaxially, the base somewhat sagittate, poricidal at the tips, the pores lengthening to slits with age. Ovary globose, glabrous; style 1–1.2 cm long, glabrous; stigma clavate or capitate, the surface minutely papillose. Fruit a globose berry, ca. 1.5 cm in diameter, reddish orange when mature, the pericarp apparently thin and somewhat shiny; fruiting pedicels ca. 2.5 cm long, ca. 1.5 mm in diameter at the base, pendent or spreading; fruiting calyx lobes appressed and covering the lower third to half of the berry. Seeds 5–10 per berry, ca. 3 mm long, ca. 2.5 mm wide, ovoid reniform, brownish red, the surfaces shallowly pitted, the testal cells sinuate in outline.

Figure 7. 

Solanum guineense L. Plate 323 from Icones Plantarum Rariorum vol. 2 (Jacquin 1792/1793, as Solanum aggregatum Jacq.), for dates of publication of Jacquin’s Icones see Schubert (1945). Reproduced with permission of the Natural History Museum Library.

(Figure 8). Endemic to the Cape Region of South Africa.

Figure 8. 

Distribution of Solanum guineense L.

Dunes and strand vegetation near the sea, from sea level to 100 m elevation.

South Africa: coastal nightshade.

(IUCN 2014). Least Concern (LC). EOO 89,953 km² (LC), AOO 24 km² (EN). Solanum guineense has a relatively wide range in South Africa, and our calculated AOO indicating conservation concern is likely due to the number of specimems we have examined for this study. The species occurs in protected areas around the Cape, and although not weedy, appears to be common, judging from the photographic records in the online community nature recording site iSpot (http://www.ispotnature.org/communities/southern-africa).

Solanum guineense is a distinctive species, with sessile inflorescences bearing only a few flowers with campanulate to spreading corolla lobes, fleshy leaves and bright orange fleshy berries (Fig. 7). The only other species with which it could be confused is the sympatric and vegetatively somewhat similar S. africanum, with branched inflorescences with more, smaller flowers and blackish purple berries. Solanum africanum has a winged stem and rhomboid leaves, while S. guineense has a rounded stem and oblanceolate or obovoid leaves. Solanum guineense was long known by the later name S. aggregatum; it was only in the 1950s that the correct name for this South African taxon began to be used (Heine 1960). The name S. guineense (L.) Mill. is still occasionally used for the Morelloid clade species correctly called S. scabrum Mill., the Garden Huckleberry (Edmonds 2012), and is based on the basionym S. nigrum var. guineense L.

In describing S. guineense, Linnaeus apparently copied the locality “Guinea” from Boerhaave (1720). Heine (1960) suggested that Linnaeus used the locality pertaining to S. nigrum var. guineense L. rather than to Boerhaave’s “Solanum africanum lignosum, folio atroviridi angusto oblong obtuso” (Boerhaave 1720). He then later tried to correct his mistake (Linneaus 1771) by transferring this morphologically unusual species to the genus Atropa L. as Atropa solanacea L. Bitter (1917) then used the later name S. aggregatum for this taxon, and also as the basis for his subgenus Lyciosolanum.

The unusual few-flowered inflorescences and flowers with petals that only spread at the tips (or at least when dry looking somewhat campanulate) led Bitter (1917) to erect subgenus Lyciosolanum. Seithe (1962) and subsequent authors (D’Arcy 1972) followed this until molecular data showed S. guineense was nested within the paraphyletic “non-spiny” grade of the larger monophyletic Solanum (Bohs 2005).

In describing S. sempervirens, Philip Miller (1768) cited the Linnaean polynomial for S. guineense but with a word left out (“Solanum caule inerme fruticoso, foliis [ovatis] integerrrimis, pedunculis lateralibus filiformibus”). He obviously did not know the species from live plants; he does not describe it in English as he did other species in the work. We think he was equating his S. sempervirens with the plant named S. guineense with the same polynomial in Linnaeus (1753) and consider the names homotypic.

Solanum aggregatum was described from material cultivated in Vienna (Jacquin 1791). We have found no original material, but Atropa solanacea is cited in the protologue making this name homotypic with it (and with S. guineense).

Dunal used two specimens collected by J.F. Drège as the basis for his S. dasypus (Drège s.n.) and S. monticolum (Drège “Lycium 7865”). They represent leaf shape variants of S. guineense, and the label “Lycium 7865” indicates the difficulties collectors had identifying this as a species of Solanum.

No original material has been found for S. bachmannii, but we are accepting Bitter’s (1917) placement of it as a variant of what he called S. aggregatum. Dammer (1906) differentiated his new species from S. aggregatum by its thicker leaves and 4-merous flowers.

South Africa. Eastern Cape: Coernie River, near Enon, Uitenhage Div., Baur 153 (K); near Graaf Reinet, 1866, Bolus 51 (BM, K, S); along the Sunday River near Monkey Ford, Burchell 2885 (G-DC, K, LE); Uitenhage, Redhouse, May 1912, Rogers s.n. (BM); in the forests of Adow, and on the banks of the Zwartkop River, district of Uitenhage, Zeyher 508 (BM, K, NY). Northern Cape: Garies, 9 miles NNW of Garies, 24 Sep 1948, Acocks 14946 (K, S). Western Cape: Stikland, between Strand and Pearl Roads, Jul 1932, Acocks 403 (S); Kanonberg, S spur, overlooking Bottelary Road, 1 Jul 1933, Acocks 2767 (S); above Victoria Road between Camps Bay and Clifton, 22 May 1935, Acocks 4561 (S); Nortier Reserve, ca. 8 km N of Lambert’s Bay, 10 Jul 1970, van Breda 4164 (K); Cape of Good Hope, Cap. Bona Spei (S sheet - ‘Tafelberg [Table Mountain]), Drège 178 (BM, E, LE, S); Kalk Bay Mountains, at summit R, 7 Apr 1934, Galpin 12630 (K); Van Rhyns Pass, near top just below TMS system, 15 Oct 1976, Goldblatt 4326 (K, S); between Hout Bay and Chapman’s Peak, 27 Jun 1945, Leighton 987 (NY); Paarlberg, 24 Apr 1962, van den Merwe 996 (K); Atties Bed, (Percy Sladen Memorial Expedition to the Orange River 1910-1911), 1 Dec 1910, Pillans 5436 (K); Stellenbosch, 20 Aug 1846, Prior s.n. (K); Camp’s Bay, 11 May 1847, Prior s.n. (K); Piquetberg [Terra Capensis], 24 Jun 1896, Schlechter 7896 (G x2, K, LE); Klippies Baai, 3419 Caledon AD, Voelklip, Hermanus, 9 Mar 1980, Williams 192 (K); Kliphuewel, Farm Spieka SE of Klipheuwel, 15 Sep 1982, van Zyl 3136 (K).

Madagascar. Sin. loc., L. Humblot 509 (type material presumably destroyed at B; lectotype, designated here: P [P00349085]; isolectotypes: K [K000414188], P [P00349086, P00349087, P00349088], W [W-1889-0053791]).

Liana in the subcanopy or canopy or a scandent shrub, to 3 m tall or perhaps larger. Stems flexuous, ribbed, glabrous or pubescent with minute uniseriate dendritic trichomes ca. 0.1 mm long or less, glabrescent; new growth finely and minutely pubescent with dendritic trichomes < 0.1 mm long; bark of older stems longitudinally ridged, often exfoliating or flaking, pale grey to almost white. Sympodial units plurifoliate, the leaves not geminate, evenly distributed along branches. Leaves simple, 5.5–7.5 cm long, 2.5–3 cm wide, elliptic, thickly chartaceous, discolorous, glabrous and smooth on both surfaces except for minute dendritic and simple trichomes along the midrib; major veins 3–6 pairs, spreading at 60°-90° to the midvein, not prominent and the finer venation not visible; base equal or oblique, cuneate to truncate; margins entire, glabrous or with occasional minute dendritic trichomes; apex short-acuminate; petiole 0.6–1 cm long, canaliculate and minutely dendritic-pubescent adaxially. Inflorescences terminal or apparently lateral on long slender main branches, 0–2 cm long, unbranched, with 1–2(4) flowers, glabrous or with a few minute dendritic trichomes; peduncle absent or up to 8 mm long; pedicels 1.8–4.5 cm long, apically dilated, ridged when dry, articulated 0–2 mm from base, sparsely pubescent with trichomes like those on the stem with the branches to 0.15 mm long. Buds ellipsoid, the corolla soon exserted from the calyx tube. Flowers 5-merous, apparently all perfect. Calyx tube ca. 3 mm long, cup-shaped, the lobes 2–4 mm long, 1.5–2 mm wide at base, narrowly triangular to deltate, acute to long-acuminate at the tips, unevenly tearing for up to ca. 2 mm at the sinuses, often tinged purple in live plants (e.g., Tosh et al. 100) evenly and sparsely pubescent with minute dendritic trichomes 0.1–0.2 mm long. Corolla 2–2.5 cm in diameter, violet to deep purple with a white centre (fide Schatz & Villiers 1820), stellate, lobed almost to base, the 8–10 mm long, 4–5 mm wide, ovate to linear, finely dendritic-pubescent abaxially, the trichomes longer and denser at the margins and tips. Stamens equal; filament tube 0.5–1 mm long; free portion of the filaments ca. 1 mm long; anthers ca. 3.5 mm long, ca. 1.5 mm wide, apparently free but close together, ellipsoid, smooth abaxially, poricidal at the tips, the pores clearly delineated and not lengthening with age. Ovary conical, glabrous; style 9–10 mm long, protruding 3–3.5 mm above the anthers, straight, glabrous; stigma clavate or capitate, minutely papillose. Fruit a globose berry, green when immature; fruiting pedicels not markedly elongating or woody. Seeds not known from mature fruit.

Figure 9. 

Solanum humblotii Dammer. A Flowering branch B Flower bud C Open flower D Fruiting branch E Berry F Simple trichome G Dendritic trichome. (based on: A–CRalisamana et al. 96; D–GTosh et al. 100). Scale bar: A, D = 3 cm; B, C = 1 cm; E = 1.5 cm; F, G = 0.2 mm. Drawn by Lucy T. Smith.

(Figure 10). Endemic to northern Madagascar in the province of Toamasina and on the island of Nosé Mangaby.

Figure 10. 

Distribution of Solanum humblotii Dammer.

Littoral forests on white sand and inland eastern rainforests; sea level to 700 m elevation.

None recorded.

(IUCN 2014). Near Threatened (NT). EOO 20,941 km² (NT), AOO 40 km² (EN). Solanum humblotii is confined to wet forests (see below), and is rarely collected. Given the decreasing extent of wet forests in Madagascar, this species is certainly of conservation concern, but it does occur in or near some forestry reserves, so may have some degree of protection.

Solanum humblotii is a forest liana with minute dendritic pubescence, triangular to long-triangular calyx lobes and thickly chartaceous discolorous leaves with an apiculate tip. The name S. humblotii has been mistakenly applied S. truncicola following the synonymy established by D’Arcy and Rakotozafy (1994), and to S. madagascariense though misidentification.

The vegetative morphology of Solanum humblotii is very similar to some populations of the widespread S. madagascariense. The two species can be distinguished easily on inflorescence size and calyx morphology. The inflorescence of S. humblotii has only 2–3 (exceptionally 4) flowers on long filiform pedicels and is never branched, while that of S. madagascariense is many times branched with many flowers except on some aberrant specimens; calyx lobes are 3–4.5 mm long in S. humblotii, and up to 1 mm long in S. madagascariense.

Specimens here recognised as Solanum truncicola were treated as S. humblotii by D’Arcy and Rakotozafy (1994), where the two were treated as synonyms. The two species are similar, and prior to our study S. humblotii was only known from the type collection. Further collecting in the wet forests of northern Madagascar has resulted in more specimens with which to assess the status of these two taxa (see also discussion under S. truncicola).

Solanum humblotii differs from S. truncicola by its petioles that are 6–10 mm (versus 1–5 mm) long, acuminate (versus acute) leaves, pubescent (versus glabrous) young stems, and inflorescences with a peduncle up to 5 mm long (versus no peduncle). The calyx of S. humblotii is fused in bud (Fig. 9); the tube is longer than the lobes and tears for up to 2 mm at anthesis with corolla expansion. The resulting calyx lobes are 3–4.5 mm long, triangular to narrowly triangular and acuminate, chartaceous, and sparsely covered in fine dendritic (almost scurfy) pubescence. This calyx morphology is similar to that of S. imamense, S. betroka and S. sambiranense. The calyx of S. truncicola is unlike that of any other Madagascar Solanum. It is dissected almost to the base in bud and does not tear by more than 1 mm at anthesis; the calyx lobes are linear to narrowly ovate or obovate, membranous, and usually glabrous.

Solanum humblotii is restricted to a small area of wet forest in the eastern ecoregion of Madagascar (Humbert 1955; Faramalala 1988, 1995), a habitat like that of the related wet forest climbing species S. madagascariense and S. trichopetiolatum. It is sympatric with the morphologically similar S. madagascariense and occurs considerably further south of S. trichopetiolatum; the distribution range of the epiphyte S. truncicola lies directly to the south of S. humblotii with some overlap in distribution ranges around the Moramanga area.The locality of the type collection within Madagascar is not known, but is likely to be from the region where all other specimens of S. humblotii have been collected. Dammer (1906) describes it as a shrub but the type specimens contain no such information; modern collections record a variety of growth forms (shrub, liana and epiphyte) in both primary and secondary habitats.

Udo Dammer worked in Berlin and it is likely he used specimens held there to describe S. humblotii but these are no longer extant. Of the four duplicates of Humblot 509 in the herbarium in Paris, we have chosen P00349085 as the lectotype due to its numerous flowers and excellent condition.

Madagascar. Toamasina: Parc National de Masoala, sur la route d’Ambanizana à Analambolo (25 km N de la ville d’Ambanizana), ca. 6 km NE d’Ambanizana, Fiv. Maroantsetra, 24 Jan 1996, Aridy et al. 77 (MO, NY); Zahamena, réserve naturelle N°3, 23 Mar 1941, Decary 16757 (P); Moramanga, Fanovana, forêt orientale, 10 Jul 1942, Decary 18118 (P); Tampolo Forest Station, ca. 10 km N of Fenerive, 23 Jan 1986, Dorr et al. 4637 (K, MO, P, TAN, WAG); Tampolo STF, District Fénérive-Est, Canton Ampasina, Tampolo, station forestière de Tampolo, 2 Jul 2001, Ludovic et al. 110 (G, MO, P); Antandrokonely, lac Alaotra, Jun 1957, Peltier & Peltier 980 (P); forêt littorale classée de Tampolo, près du village Tanambao-Tampolo, Fenoarivo-Est, 5 Apr 1997, Ralimanana et al. 96 (MO, TAN); Maroantsetra, Nosy Mangabé, a 520 ha island 5 km from Maroantsetra in the bay of Antongil, 2 Dec 1987, Schatz & Villiers 1820 (K, MO, P, TAN, WAG); Tampola, 3 km N of Tampola Forestry Reserve, 14 Jan 2006, Tosh et al. 100 (BR, TAN).

Madagascar. Antananarivo:“croit sur les rocher escarpées dans le d’Imamou”, 1839, W. Bojer s.n. (holotype: G-DC [G00144901]).

Shrub or liana, 3-4(+) m tall. Stems flexuous, flattened to terete, sparsely to densely pubescent with densely to loosely branched dendritic trichomes 0.2-0.3 (0.5) mm long, glabrescent; new growth sparsely to more commonly densely pubescent with uniseriate dendritic trichomes to 0.5 mm long, these often drying golden or golden reddish in herbarium specimens; bark of older stems longitudinally ridged, light grey. Sympodial units plurifoliate, the leaves not geminate, on short shoots or somewhat clustered towards tips of branches. Leaves simple, 2.5–5(7) cm long, 1.5–3(4) cm wide, ovate, membranous to chartaceous, discolorous, pubescent on both surfaces with uniseriate dendritic trichomes to 0.5 mm long, sometimes slightly longer and somewhat denser in the axils of the main veins with the midrib; major veins 4–7 pairs, spreading at ca. 60° to the midvein and forming loops, the finer venation often visible; base attenuate or truncate to weakly cordate; margins entire; apex acute to acuminate; petiole slender, 0.5–1.5(2) cm long, pubescent with dendritic trichomes like those of the new growth and leaves. Inflorescences terminal, at the apex of slender terminal or lateral branches, 3–7(10) cm long, furcate (sometimes unbranched), with (4)7–13 flowers, pubescent with dendritic trichomes like those of stems and leaves; peduncle 0.5–2.5 cm long; pedicels 1.1–1.7 cm long, apically dilated, pubescent with trichomes as on the young stem, articulated less than 1 mm from base and tiny pegs; pedicel scars irregularly spaced 1–4 mm apart. Buds ovoid to ellipsoid, the corolla only about halfway exserted from the corolla tube before anthesis. Flowers 5-merous, apparently all perfect. Calyx tube 2–3 mm long, conical, the lobes 3–5 (7.5) mm long, 1–1.5 mm wide at base, deltate to linear, acute at the tips, unequal in size, tearing at the sinuses by ca. 1 mm, densely pubescent with dendritic trichomes like those on the rachis. Corolla 2–3 cm in diameter, violet or purple, lobed almost to base, the lobes 10–15 mm long, 2–6 mm wide, narrowly deltate to linear, puberulous adaxially, minutely pubescent abaxially with dendritic trichomes, these larger at the tips and margins. Stamens equal; filament tube ca. 1 mm long; free portion of the filaments 1–2 mm long, glabrous; anthers 4–5(6) mm long, ca. 2 mm wide, broadly ellipsoid, not connivent, smooth abaxially with some papillae near the pores, poricidal at the tips, the pores much smaller than anther apices, ca. 0.4 mm in diameter, not lengthening with age. Ovary conical, glabrous; style 10–13 mm long, protruding 3–5(7) mm above the anthers, laterally flattened, curved, glabrous; stigma clavate to capitate, dark, the surface smooth. Fruit a globose to elongate pyriform berry, ca. 3 cm long, 1.2–1.6 cm in diameter, apically rounded or the distal portion pointed and elongate, dark purple when mature, the pericarp thin, glabrous; fruiting pedicels 1–2.5 cm long, up to 1.5 mm diameter at base, pendulous, flexible, ridged; fruiting calyx slightly accrescent, the lobes becoming wider and forming a spreading cup around the fruit. Seeds 20–30 per berry, 4–4.5 mm long, 3–3.5 mm wide, flattened reniform, yellowish brown, the surfaces minutely pitted, the testal cells pentagonal or sinuate in outline, the lateral walls with hair-like projections to 0.1 mm long.

Figure 11. 

Solanum imamense Dunal. Flowering branch (based on Baron 1754). Adapted from D’Arcy and Rakotozafy (1994) with permission of Muséum National d’Histoire Naturelle.

(Figure 12). Endemic to Madagascar, with a broad distribution range in the west, the south, and on the high central plateau; in the provinces of Mahajanaga, Antananarivo, and Toliara.

Figure 12. 

Distribution of Solanum imamense Dunal.

Open dry forest and forest edges; often growing on rocks; 900–1000 m.

None recorded.

(IUCN 2014). Least Concern (LC). EOO 165,095 km² (LC), AOO 40 km² (EN). In common with other members of the ANS clade in Madagascar, Solanum imamense has a relatively wide distribution, resulting in an EOO indicating lack of immediate conservation concern. The paucity of collections, indicative of local rarity, coupled with the ongoing habitat threats in Madagascar, however, do indicate monitoring and further collection to assess local and regional rarity is necessary.

Solanum imamense is a fairly common liana or shrub with shallowly cordate or truncate leaves clustered towards tips of branches, large (to 3 cm in diameter) violet or purple flowers, and large anthers 4–5 mm long. The pubescence of dendritic trichomes up to 0.3–0.5 mm long is visible with the naked eye on the petioles, pedicels, inflorescences and abaxial sides of the leaves (Figs 1B, 2B).

Solanum imamense is morphologically similar and possibly closely related to S. betroka from southern Madagascar and S. sambiranense from northern Madagascar, and perhaps also the rare and poorly known S. ivohibe from the province of Fianarantsoa. Solanum imamense differs from S. betroka in its inflorescences with 7–13 (versus 1–3) flowers, larger floral parts, and leaves that are always entire (versus leaves that are frequently lobed). Solanum imamense can be distinguished from S. sambiranense by its ovate leaves 2.5–5 cm long (versus elliptic to obovate leaves 5–10 cm long) and looser dendritic trichomes 0.2–0.5 mm (versus less than 0.1 mm) long. Solanum imamense differs from S. ivohibe by its ovate leaves less than 5 cm long (versus elliptic to obovate leaves 5–7 cm long), cordate to short attenuate (versus long attenuate) leaf base, and calyx lobes more than 2 mm (versus less than 2 mm) long.

Solanum imamense has a broad ecological profile occurring occasionally in dry to mesic parts of the island in the western, central, and southern ecoregions (Humbert 1955; Faramalala 1988, 1995). In the southern part of its distribution range it is sympatric with S. betroka and in the northern part of the range with S. sambiranense.

Solanum imamense var. grandiflorum was accepted by Bitter (1917) but synonymised with Solanum imamense by D’Arcy and Rakotozafy (1994). It differs from the type variety by flower size and pubescence density, but the variation in both characters is continuous. The type specimens of both were collected by W. Bojer in central Madagascar. Solanum ankazobe was described on the basis of three collections, and was distinguished by its small leaves, smaller calyx tube, irregular tearing of the calyx and wider ovary. The type collection of S. ankazobe (Perrier de la Bâthie 9615) has leaves that fall within the range of variation in S. imamense, while other specimens cited have smaller floral parts (Perrier de la Bâthie 9577 and 9579). We consider these specimens to fall within the range of variation represented in S. imamense and treat S. ankazobe as a synonym.

Madagascar. Antananarivo: Antananarivo-Nord, Tananarive, environs de Tananarive (Anositavo), 22 Apr 1928, Decary 6276 (K, MO, P); Manerinerina, Tampoketsa d’Ankazobe, 3 Jan 1942, Decary 17170MO, (P); Betafo, s.d., Perrier de la Bâthie 9574 (MO, P); Ankazobe, Manankazo, Tangeotseha entre Ihopa et Behibotra, Dec 1925, Perrier de la Bâthie 16830 (P). Mahajanga: Marovoay, Anjiafitatra, près du MontTsialondraina (Boïna), Nov 1901, Perrier de la Bâthie 1332 (MO, P); Ambongo, entre Andranomavo et Itampitso, Sep 1905, Perrier de la Bâthie 9615 (MO, P). Toliara: Amboasary-Sud, Amboahangy, bassin supérieur du Mandrare (Sud-Est), Mont Amboahangy prés d’Esira, 25 Nov 1928, Humbert 6812 (MO, P); Sakaraha, forêt d’Analafanja au N du Fiherenana, Mar 1934, Humbert 14290 (P); Atsimo-Andrefana, Behetaheta, district et commume rural Beroroha, Fokotany, Beronono-Makay, 17 Jan 2010, Rakotovao et al. 5128 (MO); Bekily, Ampandrandava, entre Bekily et Tsivory, 1943, Seyrig 156 (MO, P).

Madagascar. Fianarantsoa: Razafinarakoto, Antambohobe, Ivohibe, 28 Nov 1951, Reserves Naturelles 3516 (lectotype, designated here: P [P00349043]; isolectotypes: P [P00349042], TAN).

Straggling shrub or occasionally a liana, ca. 2.5 m tall. Stems long and flexuous, ridged, glabrous except youngest stems unevenly pubescent; trichomes densely dendritic to echinoid, most only to 0.2 mm long, with 10–15 highly congested branches each; main stems 2–4 mm in diameter, glabrous; bark longitudinally ridged, almost white; leaf scars prominent stumps almost overlapping to 2.5 cm apart. Sympodial units plurifoliate, the leaves not geminate, the leaves clustered at tips of branches and on short shoots. Leaves simple, 5–7 cm long, 2–2.5 cm wide, elliptic to obovate, membranous, wrinkled in herbarium specimens, concolorous, glabrous on both sides except for occasional simple or dendritic trichomes ca. 3 mm long with poorly developed branches, some more densely branched dendritic trichomes on the abaxial side of the midvein; midvein raised abaxially and flat adaxially; major veins 5–6 pairs, spreading at ca. 60° to the midvein, the finer venation brown, fine and faint, with tufts of minute dendritic trichomes with few branches (domatia) in the junction between the midvein and major veins abaxially; base long-attenuate; margin entire, mostly glabrous with occasional simple or sparsely dendritic trichomes becoming more frequent towards the apex; apex acute; petiole 1–2.5 cm long, slender, flexuous, ridged, glabrous or with occasional dendritic trichomes like those on the stem;. Inflorescences terminal, at the apex of branches or short shoots, 4–5 cm long, furcate, with 10–16 flowers; peduncle 2–2.7(5) cm long; peduncle and rachis glabrous or with occasional dendritic trichomes like those on the stem; pedicels 1–2.2 cm long, apically dilated with gradual transition between the pedicel and the calyx, articulated 0–0.5 mm from base, glabrous, the pedicel scars small stumps almost overlapping to 4 mm apart. Buds ellipsoid, the corolla long-exserted from the calyx tube before anthesis. Flowers 5-merous, apparently all perfect. Calyx tube ca. 1.5 mm long, broadly cup-shaped, the lobes 0.8–2 mm long, 1–1.5 mm wide at base, deltate, acute to obtuse at the tips, glabrous with tufts of dendritic trichomes at the tips. Corolla 1–2 cm in diameter, violet, stellate, lobed almost to base, the lobes 5–10 mm long, 2–4 mm wide, narrowly ovate, glabrous in the centre of both surfaces with small simple papillate trichomes denser and longer on the margins and tip, the tips of the lobes enlarged and knob-like, perhaps fleshy in live plants. Stamens equal; filament tube ca. 1 mm; free portion of the filaments less than 1 mm long, glabrous; anthers 3.5–4 mm long, ca. 1–1.5 mm wide, broadly ellipsoid, free and clearly separated from one another, smooth abaxially, poricidal at the tips; the pores much smaller than anther apices, ca. 0.3 mm in diameter, not lengthening with age. Ovary conical, glabrous; style 0.8–1 cm long, protruding 3–4 mm above the anthers, slender, curved, glabrous; stigma capitate or distinctly bi-lobed, dark, minutely papillose. Fruit and seeds not known.

Figure 13. 

Solanum ivohibe D’Arcy & Rakot. A Flowering branch B Tufts of trichomes in vein axils on leaf undersides (domatia) (based on Humbert 13429). Adapted from D’Arcy and Rakotozafy (1994) with permission of Muséum National d’Histoire Naturelle.

(Figure 14). Endemic to Madgascar in the Ivohibe and Andringitra areas of Fianarantsoa province.

Figure 14. 

Distribution of Solanum ivohibe D’Arcy & Rakot.

Riparian and secondary montane forests from approximately 800 to1200 m elevation.

None recorded.

(IUCN 2014). Endangered (EN B1a, b iii). EOO 950 km² (EN), AOO 12 km² (EN). Known collections of Solanum ivohibe are currently not sufficient to document its range of occurence with any degree of confidence, but its occurrence in the fragmented wet forests of eastern Madagascar and the paucity of collections leads us to give it a preliminary status that indicates conservation concern.

Solanum ivohibe is a slender forest shrub with almost glabrous leaves on decurrent long petioles, prominent domatia on leaf undersides (Fig. 13 inset), inflorescences with a long peduncle and 10–16 flowers. It seems likely that S. ivohibecan grow as a liana. The very few collections suggest it grows along streams in mid-elevation mesic to wet secondary forests in the underexplored and exceptionally diverse area around Andringitra National Park (Lewis et al. 1996).

Within Madagascar S. ivohibe is most similar to S. sambiranense, and to some extent also with S. imamense and S. betroka. Solanum ivohibe can be distinguished from S. sambiranense by its inflorescence bearing 10–16 (versus 3–10) flowers, calyx lobes 0.8–2 mm long tearing for up to 1 mm (versus calyx lobes 4–6 mm long tearing for up to 2 mm), and minute versus larger tufts of trichomes (domatia) in the axils of the veins and midrib of the lower leaf surfaces; it also occurs further south than the distribution range of S. sambiranense. Solanum ivohibe is sympatric with S. imamense and S. betroka; it differs from these two species by its long-decurrent (versus cuneate) leaf bases, larger leaves (> 5 cm long versus shorter than 5 cm), smaller calyx, and calyx lobes < 2 mm long (versus usually > 2 mm long). D’Arcy and Rakotozafy (1994) considered S. ivohibe to be a relative of the Mayotte endemic S. macrothyrsum but with smaller leaves and inflorescences; it shares features with both S. macrothyrsum and S. sambiranense. The anthers of S. ivohibe are longer than those S. macrothyrsum (3.5–4 mm versus 2.5–3 mm), the calyx lobes are somewhat longer (0.8–2 mm versus under 0.5 mm) and more deeply divided.

Solanum ivohibe appears to occupy a somewhat higher elevation, higher moisture, and more closed canopy environment than the similar species S. betroka in the arid south, S. sambiranense in fairly dry north-west, and S. imamense in mesic niches, and the distribution range of S. ivohibe does not overlap with these species. Solanum ivohibe apprears to be sympatric with S. madagascariense around Andringitra National Park and the surrounding forests although S. madagascariense occurs in wetter forest.

The species concept of S. ivohibe adopted here has little in common with that of D’Arcy and Rakotozafy (1994). The protologue lists five collections of Solanum ivohibe and places the species in section Lemurisolanum. In our view, two of the cited collections represent other taxa: Humbert 13429 (P00349045, from Ankazondrana), that was used for the illustration in the original description, belongs to our circumscription of S. madagascariense and Peltier & Peltier 980 (P00349044, from Toamasina) belongs to our circumscription of S. humblotii. The type specimen, however, represents a distinct taxon and we recognise S. ivohibe here, with a narrow circumscription encompassing the type and two other collections (one cited by D’Arcy and Rakotozafy [1994]) from very near the type locality.

The protologue of S. ivohibe cites a holotype at P. There are in fact two duplicates, one of which (P00349043) is clearly marked as such in D’Arcy’s handwriting; we select this specimen here as the lectotype of S. ivohibe.

Madagascar. Fianarantsoa: Ambalavao, Andringitra, edge of Zomandao River, 15 Nov 2010, Rakotonasolo & Cribb RNF-1674 (K); District d’Ivohibe R.N.V., 28 Nov 1951, Réserves Naturelles Madagascar 3523-RN (P).

Mayotte [French Overseas Department]: Maore (Grande Terre), forêt de Combani, 6 Nov 1884, L. Humblot 387 (second stage lectotype, designated here; first stage designated by D’Arcy & Rakotozafy 1994, pg. 100: P [P00184304]; isolectotypes: BM [BM000887183], P [P00184305], P [P00184306], P [P00184307], K [K000414185], W [W1889-0038295]).

Liana of forest canopy, height unknown. Stems flexuous, terete, glabrous, green; new growth glabrous or minutely papillate, green; bark of older stems smooth, light grey. Sympodial units plurifoliate, the leaves not geminate, clustered at tips of branches. Leaves simple, (5)6–8 cm long, 3–4(4.5) cm wide, oblong to obovate, membranous to chartaceous, concolorous, glabrous on both surfaces, abaxially sometimes with isolated simple to dendritic trichomes along the midvein and with tufts of tangled simple or dendritic uniseriate trichomes in the axils of the main veins, the lamina texture somewhat altered under the tufts; major veins 4–6 pairs, prominent, spreading at ca. 40° to the midvein, the finer venation faint; base attenuate and decurrent onto the petiole; margins entire; apex acute to apiculate; petiole 1.5–4 cm long, slender, canaliculate, glabrous. Inflorescences terminal, at the apex of a long slender flexuous branch, 7–10 cm long, several times branched, with 15–50 flowers, glabrous; peduncle 4.5–7 cm; pedicels apically dilated, 0.5–0.8 cm long, glabrous except for the occasional simple or sparsely dendritic trichomes just below the articulation, articulated 0–0.5 mm from base; pedicel scars 1.5–8 mm apart, becoming closer together distally, somewhat peg-like. Buds globose, the corolla soon exserted from the calyx tube before anthesis. Flowers 5-merous, apparently all perfect. Calyx tube 1.5–2 mm long, broadly cup-shaped, the lobes ca. 0.5 mm long, 1–1.5 mm wide at base, broadly deltate, rounded to cuspidate at the tips, the sinuses scarious, glabrous with tufts of translucent simple hairs at the tips and sometimes extending along the margins. Corolla 1–2 cm in diameter, mauve to lilac or white with purple towards the centre, stellate, lobed almost to base, the lobes 6–12 mm long, 1.5–4 mm wide, narrowly ovate to obovate, cucullate, glabrous adaxially, with simple to dendritic trichomes sparsely distributed abaxially, denser towards the tips, the margins densely papillate with translucent-violet trichomes ca. 0.1 mm long. Stamens equal; filament tube ca. 1 mm; free portion of the filaments 1–1.5 mm long, glabrous; anthers 2.5–3 mm long, 1.5–2 mm wide, broadly ellipsoid, spreading or very loosely connivent, smooth abaxially, poricidal at the tips, the pores much smaller than anther apices, ca. 0.4 mm in diameter, clearly delineated and not lengthening with age. Ovary conical, glabrous; style 6–9 mm long, protruding 2–3 mm beyond the anthers, slightly curved, glabrous; stigma capitate, minutely papillose. Fruits and seeds not known.

Figure 15. 

Solanum macrothyrsum Dammer. A Flowering branch B Open flower C Anther, showing round, clearly delineated pores D Simple trichome E Dendritic trichome. (based on: A–EBarthelat et al. 559). Scale bar: A = 2.5 cm; B = 7 mm; C = 3.3 mm; D, E = 0.3 mm. Drawn by Lucy T. Smith.

(Figure 16). Endemic to the island(s) of Mayotte (a political department of France geographically situated in the Comoro Islands); only recorded from the largest island Maore (=Mayotte or Grande-Terre).

Figure 16. 

Distribution of Solanum macrothyrsum Dammer.

Wet forests; 200 to 400 m elevation (calculated from locality information; elevation not recorded exactly on any specimens we have seen).

None recorded.

(IUCN 2014). Data Deficient (DD). Known from only two collections on the island of Mayotte collected 100 years apart (see below) with insufficient habitat information to assess its distribution. It is likely to be endangered based on its occurrence on a single small island and the paucity of collections; however, the island is not well-collected, so re-collection of this plant is a priority.

Solanum macrothyrsum is a rare liana endemic to Mayotte. It has large bright inflorescences of 15–50 white or violet flowers, large, membranous leaves on long petioles, a very small calyx (less than 1/8 of the corolla length at anthesis) and noticeably short, plump anthers (2.5–3 × 1.5–2 mm) on comparatively long filaments (1–1.5 mm). Solanum macrothyrsum is unusual in the group in having little pubescence on its vegetative parts, except some isolated trichomes on abaxial side of the midvein forming tufts in the vein axils (domatia) (see Fig. 15). The four duplicates of the type collection show considerable variation in leaf size, leaf thickness and venation; this perhaps represents leaves growing in the sun and in the shade or the type could have been gathered from several plants.

Since its original description by Dammer (1906), S. macrothyrsum been been known only from the type collection. It was rediscovered on the main island of Mayotte, Maore, in 2001 (Barthelat & Ali Sifari 559).

There are no species of Solanum on Mayotte similar to S. macrothyrsum. The species that most resembles S. macrothyrsum is S. ivohibe from eastern Madagascar: they share long petioles, decurrent leaf bases and branched inflorescences with a long peduncle. The two taxa are clearly distinct. Solanum macrothyrsum has anthers 2.5–3 mm (versus 3.5–4 mm) long, inflorescences branching 2–3 times (versus branching once), 15–50 (versus 10–16) flowers per inflorescence, peduncle 4.5–7 cm (versus 2–2.7 cm) long, and calyx lobes up to 0.5 mm long (versus 0.8–2 mm long). Solanum madagascariense is the only species with short anthers and open, lax inflorescences like S. macrothyrsum. Solanum macrothyrsum differs from S. madagascariense in its membranous (versus thick chartaceous to coriaceous) leaves, smaller leaf length to width ratio, petiole 1.5–4 cm (versus 0.4–2 cm) long, and smaller calyx, less than 1/8 (versus 1/6–1/3) of corolla length at anthesis.

Edmonds (2012), following the suggestion of R.N. Lester (pers. comm.) and Jaeger (1985) suggested that S. macrothyrsum was synonymous with S. benderianum (here treated as a synonym of S. runsoriense) from Ethiopia, Uganda and Kenya. Bitter (1917) also placed S. macrothyrsum as a relative of the S. terminale alliance (his section Afrosolanum) rather than with the Madagascar endemic species. There are numerous differences between these taxa: the calyx lobes of S. macrothyrsum are less than 0.5 mm long while the calyx lobes of S. benderianum are 2–4 mm long; the petioles of S. macrothyrsum are often longer than ½ of the leaf length while the petioles of S. runsoriense are less than 1/3 of the leaf length. In addition, the anthers of S. runsoriense have pores that elongate to lateral slits following dehiscence, while S. macrothyrsum, like the Malagasy members of this group, has anthers with distinct pores that never elongate. Solanum terminale also occurs in the Comoro Islands, but is known there from only a few collections (see discussion and specimens examined for S. terminale). Solanum macrothyrsum differs from S. terminale in its anthers that never become longitudinally dehiscent, its more openly branched inflorescences with widely spaced flowers, and its tufts of trichomes in the axils of the main leaf veins on the abaxial surfaces.

Bitter (1917) cites duplicates of type collection from B and P. Dammer almost certainly worked from the B duplicate which is now destroyed. D’Arcy and Rakotozafy (1994) stated that the lectotype is held at P but do not mention which of the four duplicates they chose. Of these one marked in pen as lectotype, two marked as isolectotypes and one is not annotated with a type label. We have selected the duplicate (P00184304) annotated as “lectotype” (although it is not in D’Arcy’s handwriting) as the second stage lectotype for S. macrothyrsum. Edmonds (2014) was apparently unaware of this lectotypification when she designated as “lectotype” a Kew duplicate of Humblot 387; her lectotypification is superfluous, despite D’Arcy and Rakotozafy (1994) not having stated “designated here” and identifying a particular sheet.

Mayotte (French Overseas Department). Maore: Grande Terre, Tsararano, Reserve Forestière de Tchaourembo, 20 Oct 2001, Barthelat & Ali Sifari 559 (G, K, MO, P).

Madgascar. “In Madagascar”, Collector Unknown (holotype: G-DC [G00144951]).

Liana or small tree (Gentry 11852) to 8 m. Stems terete, flattened or faintly ridged, glabrous to sparsely puberulent with simple unicellular papillae ca. 0.05 mm long, or variously pubescent with a mixture of uniseriate dendritic or arachnoid trichomes to 0.5 mm long, glabrescent or the pubescence less dense with age; new growth glabrous or pubescent with dendritic or arachnoid trichomes like those of the stems; bark of older stems smooth or longitudinally ridged, reddish brown, brown, or yellowish brown, somewhat corky on stems > 1 cm in diameter. Sympodial units plurifoliate, the leaves not geminate, evenly distributed along young branches. Leaves simple, (1.5) 3–9 (12) cm long, (1.2) 2–3 (4.5) cm wide, obovate to oblong, thick-chartaceous to thin-coriaceous, often shiny, concolorous to somewhat discolorous, glabrous, sometimes with dendritic trichomes on the midvein on both sides of the lamina; major veins 5–12 pairs, spreading at 60–90° to the midvein and forming loops, the finer venation usually faint or not visible; base cuneate to truncate, sometimes attenuate; margins entire, rarely lobed with a single lobe basally on each side, the lobes up to 8 mm long, rounded, with shallow sinuses; apex acute to acuminate, rarely obtuse and apiculate; petiole 0.4–2 cm long, canaliculate, usually glabrous, less often finely dendritic-pubescent, flexuous and sometimes twining around supports (e.g., Humbert 31597, Miller & Randrianasolo 4339). Inflorescences terminal at the apex of branches, (2.5)5–20(25) cm long, furcate or several times branched, with (8)15–45(100) flowers, glabrous or with variable dendritic pubescence paralleling that of the stems; peduncle 1.5–5 cm long; pedicels 0.4–1.1 cm long, apically dilated, always glabrous, when the rachis is pubescent a clear boundary line visible between the glabrous petiole and the pubescent rachis (a few trichomes occasionally found at the pedicel base) , articulated 0–2 mm from base; pedicel scars irregularly spaced 1–4 mm apart, often appearing as apically dilated pegs. Buds globose or broadly ellipsoid, the corolla soon exserted from the calyx tube. Flowers 5-merous, apparently all perfect. Calyx tube 2–3 mm long, broadly cup-shaped or conical, the lobes up to 1 mm long, 1.5–2 mm wide at base, often irregular or almost absent, broadly deltate, rounded to cuspidate at the tips, glabrous or with sparse short simple trichomes; margin often thickened, with dense tufts of simple hairs at the tips. Corolla 1–2 cm in diameter, white to violet, stellate, lobed almost to base, the lobes 4–10 mm long 1.5–2.5 mm wide, narrowly deltate to linear, sometimes aristate with a puberulous appendage ca. 0.5 mm long arising from the adaxial surface of the lobe just below the apex, glabrous adaxially, glabrous to puberulous abaxially with dendritic trichomes that are longer at the lobe tips. Stamens equal; filament tube 0.5–1 mm; free portion of the filaments 1–2 mm; anthers 2.5–4 mm long, ca. 1.5 mm wide, broadly ellipsoid, usually somewhat connivent, smooth or papillose abaxially, poricidal at the tips, the pores about the same diameter as the anther apices, clearly delineated and not lengthening with age. Ovary conical, glabrous; style 6–12 mm long, protruding 1.5–4 mm beyond the anthers, straight or curved, glabrous; stigma clavate to capitate, the surface smooth to minutely papillose. Fruit a globose berry, sometimes ellipsoid, 0.5–1.2 cm diameter, black or purplish black at maturity, the pericarp thin, collapsing on drying to reveal the outline of the seeds, glabrous; fruiting pedicels 1–1.2 cm long, 0.5–0.7 mm diameter at base, pendent to spreading; fruiting calyx slightly accrescent, the lobes becoming woody with a light-coloured margin. Seeds 20–40(+) per berry, 1.5–4 mm long, 1–2.5 mm wide, ovoid reniform or somewhat flattened, golden-orange or reddish brown, the surface deeply pitted, the testal cells pentagonal or slightly sinuate in outline.

Figure 17. 

Solanum madagascariense Dunal. A Flowering branch B Berry showing thin pericarp through which seeds are visible (based on: A, Bosser 16852BHomelle s.n.). Adapted from D’Arcy and Rakotozafy (1994) with permission of Muséum National d’Histoire Naturelle.

(Figure 18). Endemic to Madagascar, throughout central and eastern parts of the island, with a few records from humid forests on the western part of the island.

Figure 18. 

Distribution of Solanum madagascariense Dunal.

Humid and subhumid forests; sometimes found in disturbed vegetation by the roadside; 0–1500 m elevation.

Madagascar. Antsiranana: vahimasina (Humbert 18109), vahimbingy (RN Madagascar 2738, Miller & Randrianasolo 4563), vahinazo (RN Madagascar 8388), voajaboala (Miller & Randrianasolo 4329); Fianarantsoa: keranzy (Anon. 4026), vahimaitso (Malcomer et al. 1581), vahivahy (Randriantafika 15). No uses recorded.

(IUCN 2014). Least Concern (LC). EOO 551,384 km² (LC), AOO 436 km² (EN). Solanum madagascariense is a common liana, and occurs in several different forest types, including in some protected areas. Its local rarity and patchiness of distribution, along with its range of morphological varability (see below) suggest further studies as to local abundance are necessary.

Solanum madagascariense is a liana with prominent terminal inflorescences of 15–45 white to deep purple flowers (Fig. 1C), sturdy branches, and thick leaves. It occurs throughout Madagascar’s wet forests which are situated predominantly on the eastern coast, adjacent parts of the High Plateau, and northern parts of the island. It is the most common and variable species of endemic non-spiny Solanum.

Solanum madagascariense is similar and possibly closely related to the rare and local species S. trichopetiolatum and S. humblotii. It can be distinguished from S. trichopetiolatum by its glabrous petioles (versus petioles with long simple trichomes 0.5–0.15 mm long); S. trichopetiolatum also has looser inflorescences with finer branches and fewer flowers, a greater tendency towards discolorous oblong leaves and is restricted to a narrow area of Antsiranana. Solanum madagascariense differs from S. humblotii in its large, many-branched inflorescence with many flowers; S. humblotii has an unbranched inflorescence with few flowers and is restricted to the northern part of Madagascar in Toamasina.

Solanum madagascariense as delimited here encompasses great range of variation. It is possible to isolate groups of specimens with small long narrow leaves, groups of specimens with wide coriaceous leaves and fewer veins, and groups of specimens with sparse inflorescences and hariy leaves, but intermedidates between all these forms are common. The name S. apocynifolium has been used to describe individuals with tomentose stems and smaller leaves. Variation in indumentum is continuous with that observed in other populations of S. madagascariense, and leaf size seems to be largely determined by ecological factors. Solanum apocynifolium was accepted by Bitter (1917), tentatively accepted by D’Arcy and Rakotozafy (1994) with acknowledgement of continuous variation, and accepted at the level of variety by the late R.N. Lester (unpublished manuscript). Forms recognised as the two taxa are the extremes of a range of morphological variation and are here considered to be conspecific. Solanum nitens is a smaller glabrous variant of S. madagascariense with shiny subcoriaceous leaves and a shrubby, densely branched growth form that grows in drier, more central areas of Madagascar. It was accepted by Bitter (1917), reduced to a variety by D’Arcy and Rakotozafy (1994) and considered a synonym of S. madagascariense by Lester (unpublished manuscript). We agree with Richard Lester’s assessment and S. nitens is included in S. madagascariense as an arid environment variant. Solanum antalaha is a wet environment variant of S. madagascariense occurring further north, representing mature or shade dwelling individuals. Solanum antalaha has glabrous leaves, petioles, stems, and corolla, and leaves with fewer veins; it was described as having larger anthers but these are less than 3.8 mm long on the type specimen, within the variation range of S. madagascariense (2.5-4 mm long). Solanum marojejy was described as a Marojejy endemic with dorsally papillose anther surfaces and glabrous petioles; both of these features, however, are commonly observed in populations of S. madagascariense from other localities. Solanum marojejy is here considered to be conspecific with S. madagascariense. Solanum clerodendroides is a specimen of S. madagascariense almost certainly incorrectly labelled as collected in Nigeria (fide H. Heine 1967, in sched.)

Unusually large papillae seen on the abaxial anther surface of some collections have been postulated to restrict access to pollen or provide support or orientation cues for pollinating bees (D’Arcy 1992). Only three specimens with lobed leaves have been seen, but lobed leaves may be more common in juvenile plants as is true in the Dulcamaroid clade (Knapp 2103). An unusual specimen at P from a cultivated plant in the garden at Antananarivo (s. coll. 2174, P04063654) is from a plant with inflorescences on many short branches and only 2-3 flowers per inflorescence and somewhat resembles S. humblotii, but morphologically conforms to S. madagascariense in terms of floral form, calyx size and leaf morphology.

We have chosen Forsyth-Major 15 [K000414184] as the lectotype for S. madagascariense Dammer (nom. illeg., a later homonym of S. madagascariense Dunal) as it is the only unambiguous duplicate of the type collection number we have found. It is probable that the sheet at BM labelled Forsyth-Major 55 [BM000887181] is another duplicate (and thus an isolectotype), curatorial annotation on the BM sheet suggests 55 may be an error for 15.

The protologue of S. antalaha cites a holotype at P; of the two duplicates of the type collection P00349362 has been selected as the lectotype because it annotated as “holotype” in W.G. D’Arcy’s handwriting.

Madagascar. Antananarivo: Manjakandriana, Mandraka, Aug 1906, D’Alleizette 988 (P); Tampoketsa de Ankazobe, 5-12 km E of highway 31 km N of Ankazobe, 19 May 1974, Gentry 11852 (MO, NY); Antananarivo-Nord, la forêt à l’Est d’Ambakolaona, 11 Nov 1912, Humbert & Viguier 1265 (P); mont Kalambatitra et ses abords, Nov 1933, Humbert 11901 (MO, P); foret d’Ankilahila, 16.2 km SE de Tsinjoarivo, le long de la riviere d’Andrindrimbola, 21 Jan 1999, Messmer & Andriatsiferana 744 (G, K); Andramasina, Ambohimiadana, Kelilanina, Antsararoloha, 15 Dec 2009, Rakotonasolo et al. RNF-1535 (K); forêt d’Andranomay à 2 km à l’Est d’Andranomay et 13 km au SE d’Ankazobe, 20 Dec 1996, Randrianaivo 47 (BR, MO); Ambohitantely RS, à 36 km au Nord Est d’Ankazobe, 1 km à l’Est des Batiments de l’Angap, 14 Jan 1997, Randrianaivo et al. 59 (MO, NY, TAN). Antsiranana: Ampasindava, forêt de Betsitsika, 12 Dec 2008, Ammann et al.193 (G); Anamalaho, massif de Makirovana, au Nord-Ouest de Sambava, 22 Aug 2007, Andriamihajarivo et al. 1256 (TAN); Tsaratanana Massif, along path from Mangindrano to Mahatsabory Mica, 19 Oct 2001, Birkinshaw et al. 978 (MO, NY, P, TAN); montagnes entre le haut Sambirano et le haut Maivarano (entre Mangindrano et Ampanompia), Nov 1937, Humbert 18109 (P); environs d’Andapa, bassin de la Lokoho, 1948, Humbert & Capuron 21939 (P); Reserve Speciale Manongarivo, E of Ankaramy, Bekolosy, 7 Dec 1992, Malcomber et al. 1998 (BR, G, K, MO x2, NY, P); Reserve Naturelle Marojejy, along the trail to the summit of Marojejy Est, NW of Mandena between the first and second camps, 6 Oct 1988, Miller et al. 3413 (K, MO x2, P, TAN); commune rurale de Daraina, forêt de Binara, 20 Nov 2005, Nusbaumer & Ranirison 1637 (G,K); commune rurale de Bealampona, village de Mandritsarahely, Sud-Ouest d’Andapa, 18 Oct 1994, Ravelonarivo et al. 418 (MO, NY, P); Ambilobe, Beramanja, fôret de Salabenono, sur la chaine Galoko, 7 km au sud-est d’Anketrabe, 25 Nov 2006, Razafitsalama & Torze 1145 (MO, TAN); Marotolana, Ampanompy, 5 Apr 2001, Razakamalaka et al. 104 (MO, TAN); canton de Manaka est, district d’Antalaha, Rés. nat. 3, 9 Nov 1952, Réserves Naturelles Madagascar 4480 (P); Marozato, district d’Ambanja, Rés. 4, 18 Nov 1952, Réserves Naturelles Madagascar 4499 (P, TAN); Sambava, Marojejy National Park, path down from camp 3 (camp Simpona) to camp 2 (camp Marojejia), 17 Oct 2011, Vorontsova et al. 498 (K, TAN); Cap Masoala Grand Parc, haut vallée d’Anaovanandrano, 26 Sep 2003, Wohlhauser et al. 648 (G). Fianarantsoa: Fianarantsoa rural, forêt d’Ambondrombe, Anonymous 4026 (P); Betanatana Forest Reserve, Fargangana, Ankarana, Manobo, 28 Aug 2008, Bussmann et al. 15257 (MO, TAN); forêt basse au PK 298 (Sud Ambositra), 12 Dec 1974, Cremers 3635 (MO, P); Vondrozo, province de Farangana, bord de route en forêt, 9 Sep 1926, Decary 5235 (P); Ambositra, Ambohimitombo, 21 Dec 1894, Forsyth-Major 325 (K); Bassin de l’Itomampy, mont Papanga prés de Befotaka, Dec 1928, Humbert 6912 (P); massif de l’Ivakoany, pentes orientales du massif, 1933, Humbert 12240 (P); forêt ombrophile d’Ambatofitorahana, 2 Mar 1960, Keraudren 229 (MO); Parc National Ranomafana, Parcelle I, south of Ambohimiera, valley of Sakavolo river, 15 Sep 1992, Malcomber et al. 1581 (BR, G, K, MO x2, NY, P); Réserve Spéciale de Manombo, parcelle 2, 37 km au SW de Farafangana, 21 Aug 1995, Messmer & Rakotomalaza 46 (TAN); Reserve Naturelle Integrale d’Andringitra, 50 km S of Ambalavao, near abandoned meteorological station above Ambalamarina, 12 Jan 1987, Nicoll 236 (MO, TAN); limite nord de la Réserve Spéciale d’Ivohibe, 7.5 km ENE d’Ivohibe, 11 Oct 1997, Rakotomalaza et al. 1398 (G, MO, NY); Ambositra, Ambalamanakana, 28 Jan 2005, Ralimanana et al. 449 (K); forêt dense humide de l’Est d’Andranobetokana, Ampasimadinika, Marofototra, Mananjary, 16 Jan 1999, Randriantafika et al. 15 (MO); 2 km Ouest d’Andrambovato, bord de la rivière Tatamaly, haut versant, Fivondronana Tolongoina., 19 Oct 2000, Randriantafika 176 (MO, NY, P); Ambalavao, 23 Jan 1958, Réserves Naturelles Madagascar 9981 (P); 7 km W of Ranomafana, S of the Namorona River at Duke University Primate Center study site and along road N of river, eastern domain, 28 Oct 1987, Schatz et al. 1713 (BR, K, MO, P); Ambalamanakana, 18 Dec 1959, Schlieben 8197 (BM, BR, G, TAN). Mahajanga: ruisseau Ambatoharanana, Andranomena, Matsoandakana, 14 Feb 2008, Bernard et al. 813 (TAN); Tsitondroina, 16 Apr 1941, Herb Jard Bot Tananarive 4812 (P); Tsaravilona, Amparihy, Androva, suivant une ligne de crête vers le nord est, 26 Feb 2008, Ravelonarivo et al. 3042 (K); Bealanana, Mangindrano, Ambohimirahavavy, Antsahivo, point côté, 20 Oct 2005, Wohlhauser et al. 786 (MO, P). Toamasina: Parc National de Zahamena, Fivondronana, Antanandava, Antenina, 31 Jan 2002, Andrianjafy et al. 273 (MO, NY, P); Aloatra-Mangoro, Ambatondrazaka, Didy, Antsevabe, Sahananto, Rivière de Sahananto, 12 Dec 2005, Andrianjafy et al. 1535 (TAN); Ambanizana, Maroantsetra, Anjahana, Ambanizana, 16 Sep 2002, Antilahimena 1405 (MO, NY); forêt d’Analalava, sous-prefecture Tamatave II, Morarano, à 7 km du SO de Foulpointe, 10 Mar 2005, Birkinshaw et al. 1442 (TAN); Ambatondrazaka, Cours, G. 1058 (P); Moramanga, Forêt de Perinet à 7 km à l’Est de Perinet vers Tamatave, 28 Feb 1971, Cremers 1481-3 (P); Ambodimanga à Tamatave, 11 Oct 1957, Herbier de la Station Agricole de l’Alaotra 2807 (MO); Onibe, massif de l’Andragovalo au Sud-Est du lac Alaotra, Rés. Nat. 3 dite de Zekamena, bassin de l’Onibe, Oct 1937, Humbert 17746 (MO, P); Maroantsetra, massif de l’Anjanaharibe (pentes et sommet Nord) à l’Ouest d’Andapa, 1951, Humbert & Cours 24533 (P); Betampona Rèserve Naturelle Intègrale, 40 km NW of Toamasina, 27 Sep 1993, Lewis & Razafimandimbison 639 (MO); Forêt de Mantady, road to N (Tamatave), 29 Oct 1993, Nek et al. 2021 (BR, TAN); Ikongo, Ranomafana, 50 km E of Fianarantsoa on Mananjary road, across R. Namorona from Ambatolahy, 4 Nov 1986, Nicoll 139 (K, MO x3, P, TAN); bois des environs de la baie d’Antongil, 1912, Perrier de la Bâthie 8686 (P); Vatomandry, Ambalabe, Ambinanindrano II, hameau villageois Tobin’i Foara, le long du sentier Nord, 4 Oct 2005, Ranaivojaona et al. 1185 (MO,P); canton de Varaina Manatsambaliny est, district d’Ambatondrazaka, 13 Nov 1948, Réserves Naturelles Madagascar 1598 (P); Parc National de Masoala, excursion d’Andranobe à Bedinta, entre Ambatoavo et Bedinda, Nov 2001, Sauquet et al. 86 (P); Ankirindro Massif, slopes above the village Ambodivato, ca. 5 km NW of Ambinanitelo along the Vohimaro River, 20 Nov 2002, Schatz & Antilahimena 4018 (MO,NY); Vohibinany, Anivoranokely, Ambidimanga, 21 Sep 1954, Vigreux 15491 (P). Toliara: Betroka, Ivahona, Réserve Spécial de Kalambatritra. Forêt d’Analamaro, 5 Nov 2005, Andrianjafy et al. 497 (MO); Morondava, Bara, 1880, Cowan s.n. (BR,P); col de Tsitongabarika, 16 Nov 1932, Decary 11017 (P); bassin de la Manampanihy, Col de Fitana, 15 Oct 1928, Humbert 6050 (P); massif du Beampingaratra, vallée de la Maloto, 1928, Humbert 6302 (NY, P); N of Taolagnaro town; along Andranoroa River, border of Marosoy Forest and Andohahela Reserve, 2 Dec 1989, McPherson 14591 (MO).

Madagascar. Antsiranana: partie occidentale du Massif de Marojejy (Nord-Est) de la vallée de l’Ambatoharanana au bassin supérieur de l’Antsahaberoka, 1200-1400 m, 9 Nov – 2 Dec 1959, H. Humbert & P. Saboureau 31469 (lectotype, designated here: P [P00352407]; isolectotypes: P [P00352405], P [P00352406], MO [MO-277613]).

Liana or epiphyte growing up to 4 m above ground. Stems somewhat ribbed or winged, glabrous, the wings to 2 mm wide on herbarium specimens; new growth completely glabrous; bark of older stems longitudinally ridged (when dry), brown. Sympodial units plurifoliate, the leaves not geminate, evenly distributed along branches. Leaves simple, 10–20 (31) cm long, 2.5–4.5 (6) cm wide, linear to elliptic or obovate, thick coriaceous to fleshy and probably somewhat succulent, concolorous, glabrous on both surfaces; major veins 4–5 pairs, not easily visible, the finer venation not visible; base cuneate to rounded; margins entire, sometimes revolute in dry material; apex acute to acuminate; petiole 1–2.5 cm long, thick and fleshy, often somewhat flattened and drying with prominent wings and ridges perpendicular to the axis, glabrous, possibly twining. Inflorescences terminal, at the apex of terminal branches or slender lateral branches, 7–11 cm long, furcate or occasionally unbranched, with 2–6 flowers; peduncle 4–9 cm long, less than 1 mm diameter at the base, much thinner than the stem, glabrous; pedicels 1.5–2.5 cm long, apically dilated, glabrous, drying ridged, articulated in the lower ⅓, 0.1–0.8 cm from base; pedicel scars prominent peg-like stumps, darker distally, irregularly spaced 3–10 mm apart. Buds oblong, the corolla strongly and long-exserted from the calyx tube. Flowers 5-merous, apparently all perfect. Calyx 1–2 mm long, ca. 6 times shorter than the corolla at anthesis, broadly cup-shaped, the lobes less than 1 mm long, 2–3 mm wide at base, broadly deltate, obtuse at the tips, glabrous with tufts of papillae at the lobe apices and some papillae along the margins. Corolla ca. 2 cm in diameter, white to violet-purple, stellate, lobed almost to base, the lobes 10–15 mm long, 2.5–3 mm wide, narrowly deltate to long-triangular, both surfaces glabrous, the margins densely papillate, the tips cucullate. Stamens equal; filament tube ca. 0.5 mm long; free portion of the filaments ca. 1.5 mm long, glabrous; anthers ca. 7 mm long, ca. 1.5 mm wide, ellipsoid, tightly connate, papillate abaxially, poricidal at the tips, the pores slightly smaller than anther apices, clearly delineated and not lengthening with age. Ovary conical, glabrous; style 8–9 mm long, protruding 1–2 mm beyond the anthers, filiform, straight, glabrous; stigma clavate, the surface smooth. Fruit a long-ellipsoid, fusiform or pyriform berry, (1.5)3–4 cm long, 1–2 cm diameter at maturity, with an apical beak 2–5 mm long, basally rounded or the base narrowing and the berry fusiform, ripe fruit colour not known, mature pericarp glabrous, the flesh thick and the fruit apparently spongy or woody, no seeds borne in the elongate apex; fruiting pedicels ca. 1.6 cm long, 1–2 mm diameter at the base, spreading; fruiting calyx lobes minute, becoming reflexed as the fruit enlarges. Seeds 5–8 per berry, 5–6 mm long, 3–4 mm wide, flattened reniform and imbedded in thick pulp, dull golden-yellow, the surfaces minutely pitted, the testal cells rectangular (? – only seen in immature seeds) in outline.

Figure 19. 

Solanum myrsinoides D’Arcy & Rakot. A Flowering branch B Open flowers C Berry showing tapering at both ends (based on: AHumbert & Saboureau 31429 BHumbert 22253CCours 3326). Adapted from D’Arcy and Rakotozafy (1994) with permission of Muséum National d’Histoire Naturelle.

(Figure 20). Endemic to northeastern Madagascar, in Toamasina and Antsiranana provinces.

Figure 20. 

Distribution of Solanum myrsinoides D’Arcy & Rakot.

Wet montane forests; 500–1500 m elevation.

None recorded.

(IUCN 2014). Vulnerable (VU B1a,b iii); EOO 7,482 km² (VU), AOO 52 km² (EN). Solanum myrsinoides is known from fewer than 10 locations, all in a restricted area around Antogil Bay in northeastern Madagascar. Its population density may be underestimated as it is a rarely collected canopy liana or epiphyte. It occurs in several protected areas in the region and so is not assessed here as Endangered as the small AOO might warrant.

Solanum myrsinoides is a distinctive wet forest endemic. Its large coriaceous or fleshy leaves, often epiphytic habit and apically elongated fruit are unusual in Solanum. Solanum myrsinoides seems to grow as a liana but can lose connection with the ground and survive as an epiphyte as high as 4 m in the canopy. The stems of S. myrsinoides are often winged. The thick petioles are flexuous and have a wrinkled woody texture when dry; it seems likely that these are used for climbing. Size and shape of the leaves is highly variable between collections and probably therefore plants. The peduncle and rachis are long and slender, in contrast to the thick stems (Fig. 19). It is the only Solanum species in Madagascar that is completely glabrous on all vegetative parts, with nothing but small papillae on the apices of the calyx and corolla lobes. D’Arcy and Rakotozafy (1994) report that these trichomes are sometimes branched, but we have not seen this in any of the specimens we have examined.

Solanum myrsinoides is unlikely to be confused with another species of Solanum. Some large leaved individuals of S. truncicola are highly reminiscent of S. myrsinoidesin their leaves and habit, perhaps reflecting common adaptation to montane wet forest understorey. Solanum myrsinoides can be distinguished by its calyx lobes that are less than 1 mm long (versus 4–11 mm long), inflorescences with 2–6 flowers (versus 1–2 flowers), and distinct slender peduncle 4–9 cm long (versus peduncle absent). The distribution of the two species does not overlap; S. myrsinoides occurs at lower elevations further north.

The developing fruit of S. myrsinoides has a globose basal part and a clearly distinct elongated apical beak that gradually tapers to a point (Fig. 19). At maturity the basal globose part narrows to produce a woody (in dry specimens) ovoid shape; sometimes the basal part of the fruit also narrows so the berry is fusiform (spindle-shaped) and tapers at both ends. Among the non-spiny Solanum species endemic to Madagascar, similar apically pointed fruits occur in S. betroka, S. imamense, S. sambiranense, and S. truncicola; globose berries have been observed in S. imamense, S. madagascariense, and S. trichopetiolatum. The thick, possibly spongy flesh seen in S. myrsinoides is not apparent in other Madagascar solanums, but these species are rarely collected in fruit; further field observations are necessary.

A holotype and an isotype are cited from P. There are three duplicates of the type collection at P and a single sheet was not selected at the time of description. P00352407 is marked “type” with a label attached over (and apparently thus after the determination) D’Arcy’s determination slip, indicating that perhaps it is the one D’Arcy and Rakotozafy intended as the holotype. We here select this sheet as the lectotype to avoid ambiguity because there is no evidence of the author’s selection of a particular sheet as holotype (see McNeill 2014).

Madagascar. Antsiranana: Sambava, pentes orientales du Massif de Marojejy, (N-E), a l’ouest de la riviere Manantenina, affluent de la Lokoho, 15 Dec 1948, Humbert 22504 (K, Px2); Ambatosoratra, Vallée de la Lokoho (Nord-Est), mont Ambatosoratra au Nord d’Ambalavoniho et de Belaoka, Jan 1949, Humbert & Cours 22863 (MO, P); contreforts occidentaux du massif de Marojejy (Nord-Est) près du col de Doanyanala (limite des bassins de la Lokoho et de l’Andraronga, 1949, Humbert 23142 (P); Reserve Naturelle de Marojejy, along the trail to the summit of Marojejy Est, N of Mandena, 3 Dec 1989, Miller & Randrianasolo 4675 (MO, TAN); Préfecture d’Antalaha, Sous-Préfecture d’Andapa, commune rurale de Bealampona, sud-ouest d’Andapa, Réserve Spéciale d’Anjanaharibe-Sud, village d’Andranotsarabe, suivant la route Nationale d’Andapa-Bealanana de la piste vers à l’ouest, Ambatomainty, Camp No. 2, 3 Nov 1994, Ravelonarivo & Rabesonina 475 (MO); limite entre Anjialavabe et Doany, Andapa, deuxième montagne d’Ankarongameloka, Ravelonarivo 1889 (P). Toamasina: Marovovonana, Befotsila Camp, 1 Sep 2004, Antilahimena 2694 (MO, P); Masoala National Park, N ridge of Ambohitsitondroinan’Mahalevona, just below summit, ESE of village of Mahalevona, 23 Feb 2003, Lowry et al. 6120 (MO, TAN); Antongil, environs de la Cave, baie d’Antongil, Aug 1912, Perrier de la Bâthie 8718 (P); Masoala peninsula, Ambanizana, ‘S Trail’ (S of Androka river) climbing into hills SE of Ambanizana, 1 Nov 1992, Schatz et al. 3391 (MO, P).

Uganda. Western: Ruwenzori, [rec. at Kew 13 Mar 1901], W.G. Doggett s.n. (holotype: K [K000413968])

Vine or woody liana, sometimes semi-herbaceous, to 10 m. Stems flexuous, terete, glabrous to densely pubescent with mixed simple 4–6-celled and short-branched dendritic uniseriate trichomes 0.5–1(1.5) mm long, glabrescent when older; new growth almost glabrous to densely pubescent with dendritic and simple uniseriate trichomes, when these dense the new growth appearing golden in dry material. Bark of older stems reddish brown, smooth. Sympodial units plurifoliate, the leaves not geminate, evenly distributed along branches. Leaves simple, 4–12 cm long, 2–5.6 cm wide, elliptic or less commonly ovate, membraneous, the adaxial surfaces glabrous to moderately pubescent with mostly simple uniseriate trichomes 0.5–1 mm long, in more pubescent individuals some trichomes dendritic, the abaxial surfaces glabrous or with a few simple uniseriate trichomes along the veins and margins to densely pubescent with short-branched dendritic trichomes 0.5–1.5 mm long, these often drying golden; major veins 5–10 pairs, usually yellowish beneath, especially on glabrous individuals; base acute; margins entire, if the leaves otherwise glabrous the margins have a few simple trichomes to 1 mm long near the base; apex acute to acuminate; petioles 0.7–3.2 cm long, very variable in length along the stem, nearly glabrous to densely dendritic-pubescent, sometimes twining. Inflorescences terminal, 5–15(+) cm long, lax and open, many times branched, with 20–100 flowers many open at the same time, pubescence in parallel to that of stems and leaf undersides; peduncle ).5-)2–4.5 cm long, sometimes the inflorescence branches starting very near the last stem leaves; pedicels 0.8–1.2 cm long, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter at the apex, spreading at anthesis, pubescent like the rest of the inflorescence axis, but slightly less densely, articulated at the base leaving a very minute raised portion of the axis; pedicel scars irregularly spaced 1–6 mm apart. Buds ellipsoid, the corolla completely enclosed in the calyx tube until shortly before anthesis, when young the elongate sepals spreading at the bud tips. Flowers 5-merous, heterostylous, short-styled and long-styled flowers apparently borne on different plants and the plants possibly dioecious. Calyx tube 1–1.5 mm long, open-conical, the lobes 1–2 mm long, narrowly triangular with a long-acuminate tip, usually thickened and keeled abaxially (this easier to see on glabrous specimens), glabrous to densely pubescent with mixed dendritic and simple uniseriate trichomes, even if glabrous the tips with a tuft of simple uniseriate trichomes. Corolla (1.5)2–3.5 cm in diameter, pale violet or white with a darker purple centre, stellate, lobed ca. halfway to the base, the lobes 7–9 mm long, 6–8 mm wide, spreading at anthesis, variably pubescent, from almost glabrous with dense papillae on the tips and margins to densely pubescent with minute dendritic trichomes all usually < 0.5 mm long (to 1 mm long in Taylor 1408). Stamens equal; filament tube absent; free portion of the filaments 1.5–2.5 mm long, glabrous or sparsely pubsvent with dendritic trichomes (on pubescent plants); anthers 2.5–3 mm long, 1.1.5 mm wide, ellipsoid, bright yellow, connivent to somewhat spreading, smooth abaxially, somewhat sagittate at the base, poricidal at the tips, the pores lengthening to slits with age, in dry material the pores thickened and paler at the distal tips. Ovary globose, glabrous; style of different lengths on individual plants, the short-styled plants with styles 2.5–3 mm long, held within the anther cone or exceptionally to 5 mm long and at the level of the anther tips, the long-styled plants with styles 7–9 mm long, exserted 4–6 mm beyond the anther cone, glabrous (on Wollaston s.n. [SS plant from Ruwenzori] densely dendritic-pubescent in the distal half); stigma of short styles minutely capitate, of long styles strongly bilobed or clavate, the surfaces minutely papillate. Fruit a globose berry, 0.8–0.9 cm in diameter, purple when ripe, the pericarp thin and brittle in dry material, probably shiny in fresh material; fruiting pedicels 2–2.5 cm long, tapering markedly from a base ca. 1 mm in diameter to the apex 4–5 mm in diameter, the distal half usually darker in dry material, spreading, possibly somewhat woody; fruiting calyx lobes to 0.5 cm long, spreading. Seeds 10–12(16) per berry, 2.5–3.5 mm long, 2–2.5 mm wide, ovoid reniform, reddish brown, the surfaces shallowly pitted, the testal cells very small, pentagonal in outline.

Figure 21. 

Solanum runsoriense C.H.Wright. A Flowering branch from short-styled plant B Bud from short-styled flower C Open short-styled flower D Flowering branch of long-styled plant E Open long-styled flower with long-exserted style F Infructescence G Detail of dense dendritic pubescence of leaf undersides H Elongate dendritic trichome. (Based on: A–CNapier 5130; D, E, G, HFriis et al. 3610; FMooney 7016). Scale bar: A, D, F = 4 cm; B, C = 7 mm; E = 1.5 cm; G = 5 mm; H = 0.4 mm. Drawn by Lucy T. Smith.

(Figure 22). In the mountains of eastern Africa in Ethiopia, Kenya, Uganda, and the Democratic Republic of the Congo.

Figure 22. 

Distribution of Solanum runsoriense C.H.Wright.

None recorded.

Montane forests, bamboo forests; often in open areas and forest edges; 1500–3700 m elevation.

(IUCN 2014). Least Concern (LC). EOO 1,346,193 km² (LC), AOO 200 km² (EN). Although S. runsoriense as delimited here occupies a large geographical range, it is found at high elevations on isolated mountain systems. Genetic differentiation at the population level across its range could therefore be important for conservation and should be assessed.

Solanum runsoriense is a montane forest edge species with large, openly branching inflorescences of purple (“blue”) flowers. It is not likely to be confused with any other species on the African continent; it the only species of the ANS clade with short-styled and long-styled flowers (see below, Fig. 21). Solanum runsoriense is partly sympatric with S. terminale but occurs at higher elevations and apparently in wetter forests. Solanum terminale has more deeply stellate corollas, flowers tightly clustered in groups rather than evenly and widely spaced on the inflorescence branches, and bright red rather than blackish purple berries. Pubescence is extremely variable in S. runsoriense; populations from Ethiopia (described as S. benderianum) are almost completely glabrous on stems and leaves, while populations from the Ruwenzoris in Democratic Republic of the Congo and from the Aberdare Mountains in Kenya are densely pubescent with golden dendritic trichomes. Individual populations are isolated in what has been recognised as the Afromontane (Wright 1978, 1981) or Tropic-montane Flora (Linder 2014) and limited gene exchange may allow these variants to become fixed. Flower, fruit and seed morphology are constant throughout the species range.

Edmonds (2012) placed S. macrothyrsum in synonymy with S. runsoriense; she cited Dammer (1906) and Jaeger (1985) both of whom suggested there were affinities between the two taxa. The two taxa share openly branched inflorescences and S. macrothyrsum is superfically similar vegetatively to more glabrous forms of S. runsoriense, but S. macrothyrsum has deeply stellate corollas and anthers that open with two terminal pores that never extend to slits as the flower ages, while S. runsoriense has shallowly stellate corollas and anther pores that extend to longitudinal slits with age.

Solanum runsoriense has the only member of the ANS clade that is heterostylous; in all but one of the specimens we have examined flowers on a given stem are either short-styled or long-styled. The Ethiopian collection Gilbert 138 (K000788688) is the only one we have seen with fruit and short-styled flowers on same plant. No other inflorescences with short-styled flowers had fruits, and when specimens were fruiting, all flowers in the inflorescence had set fruit. Collections are often of some sheets with flowers (short-styled) and duplicates with fruit (e.g., Schimper 1227); it is not clear if these represent branches from a single plant or different individuals. Solanum runsoriense could be either monoecious or dioecious, but most monoecious solanums have a mixture of short- and long-styled flowers in the same inflorescence (Diggle and Miller 2004; Miller and Diggle 2003; Whalen and Costich 1986) so we suspect S. runsoriense is another instance of dioecy in the genus (see Symon 1970; Symon 1979; Anderson and Symon 1989; Knapp et al. 1998; Martine et al. 2009). Field observations on the breeding system of S. runsoriense are a priority, and microscopic examination of pollen morphology to see if long-styled flowers have inaperurate pollen like other dioecious solanums (e.g., Knapp et al. 1998) might help to determine the breeding system of this species.

Engler (1892) was the first to publish the name S. benderianum, but without description; he attributed the name to Schimper and cited Schimper’s 1863 manuscript list of plants collected in Ethiopia. Wright (1906) and Dammer (1906) both used Engler’s epithet and provided descriptions, but Wright’s treatment was published in February 1906, a few months before Dammer’s that appeared in August 1906 making S. benderianum Dammer an isonym and illegitimate. Both botanists attributed the name to Schimper, cited Engler’s (1892) publication and based their descriptions on two collections (presumably different duplicates), Schimper 1227 and Scott-Elliot 7733. Wright (1906) also cited Wellby s.n. from Ethiopia. Bitter (1917) later used Scott-Elliot 7733 as the type of his var. ruwenzoriense. We have lectotypified these three names with the three different specimens used in various combinations in their protologues in order to avoid making them homotypic. Edmonds (2012) incorrectly used Wright’s (1906) mis-spelling of the name “bendirianum”; we consider this a correctable spelling mistake because Wright cited Engler’s publication in which the name was spelled in the way Schimper intended, to honour his son-in-law “Herr Bender”.

De Wildeman (1922) specified no herbarium or sheet in his description of S. longipedicellatum (a later homonym of S. longipedicellatum Bitter, a synonym of the potato species S. stoloniferum Schltdl., Spooner et al. 2004). Of the two sheets of Bequaert 4676 at BR, we have chosen that (BR0000008993151) annotated incorrectly as “holotype” by the late R.N. Lester as the lectotype because it has a label with the number and collecting locality. The isolectotype at BR (BR0000008993120) has no original label, but has a scrawled sheet in De Wildeman’s handwriting stating the differences between his species and S. runsoriense.

Democratic Republic of the Congo. Nord-Kivu: Upper Ruamoli valley, 3 Aug 1952, Ross 800 (BM); Katwah Kitumo, pistes des Beulele et a Mahonge (P.N.A. [Parc Nacional Albert = Virunga]), 12 May 1948, de Wilde 55 (BR).

Ethiopia. Addis Ababa: Addis Ababa, 1956, Mooney 6712 (K). Amhara: Semien, Uulkefit, Lumalumo, 10 Jul 1909, Chiovenda 877 (FT); West Shewa region W of-Washa Forest, 3 Dec 1984, Edwards & Tewolde 3572 (ETH); Choke Mountains, Gojjam, vicinity of the upper Ghiedeb valley, 5 Aug 1957, Evans 413 (BM, ETH, FT, K); Debre Workto Mota, 30 Oct 1981, Mesfin Tadese & Kagnew 1684 (ETH, K); Mussolini Pass, between Debre Berhan and Dobre Sina, about 200 km NNE of Addis Ababa, 23 Jul 1965, de Wilde & de Wilde-Duyfjes 7369 (BR). Oromia: Menegasha State Forest, Mount Wuchacha, 48 kms due W of Addis Ababa on Ambo road, turn off just W of Menengasha village, 21 Oct 1971, Ash 1299 (EA, K); Ghidami, Mar 1939, Benedetto 390 (FT); Bale Zone, Dolo Mena (Masslo) to Goba, 29 Oct 1984, Friis et al. 3610 (ETH, K); Mount Chilalo, a few kilometres S of mountain, track leading from road South of Asella to Ticho, 25 Nov 1968, Gilbert & Gilbert 1098 (EA, K); Ticcio track; Arsi region, 28 Nov 1966, Gilbert 138 (ETH, K); Mt. Zuquala, Nov 1994, Hylander, K. 139 (ETH); Mount Maigudo, 24 Oct 1954, Mooney 6156 (EA, FT, K, S); Debre Berhan, Wofasha, 23 Mar 1955, Mooney 6475 (FT, K); ca. 10 km N of Koffale, Gobe Livestock Farm, 13 Oct 1971, Thulin 1502 (ETH, K); Mount Wuchacha, about 15 km W of Addis Ababa, 27 Oct 1965, de Wilde & de Wilde-Duyfjes 8480 (BR, ETH, K); Arsi, Mount Borulucciu, Asella to Ticcio, E slope of Mount Borulucciu, 6 Dec 1965, de Wilde et al. 9213 (BR, K). Southern Nations, Nationalities and Peoples Region: Amaro Mountains, Mount Delo, E slope, 29 Jan 1953, Gillett 15034 (K); road from Wondo to Agere Selam [Hagere Selam], 13 km from Wondo, 24 Jan 1968, Westphal & Westphal 3157 (BR); Agere Selam [Hagere Selam], about 30 km S of Wondo, 21 Oct 1965, de Wilde & de Wilde-Duyfjes 8360 (BR, ETH).

Kenya. Central: Aberdare National Park, Aberdare Mtns., ca. 1 km W of Jerusalem Gate (West), Dist. Nyandarua, 12 Jan 1975, Croat 28375 (K, MO); Katamayu, Uplands District, Aug 1933, Napier 5130 (K, MA); Murang’a, Tuso Fishing Camp, Oct 1932, Jex-Blake 3304 (EA); Aberdare National Park, North Kinangop-Nyeri road, 30 Jul 1960, Polhill 250 (BR, EA, K). Rift Valley: Samburu, Mount Nyiru, 30 Dec 1955, Adamson 543 (EA, K); Samburu, Mount Nyiru, Mbarta forest zone, 29 Mar 1995, Bytebier et al 28 (BR, EA, K); Laikipia, district around Nyasi, Lakipia Plateau and Aberdare range, 1908, Routledge s.n. (K); Naivasha, Naivasha-Nyeri track, 28 Oct 1934, Taylor 1408 (BM).

Uganda. Eastern: Mount Elgon, Apr 1930, Liebenberg 1637 (K); Mount Elgon, western section, 300 m E of Nabulalo, 1 km SE of Maika, 29 Mar 1993, Sheil & Musingizi 1813 (K); Mount Elgon, Bulambuli, 6 Sep 1932, Thanes 650 (K). Western: Ruwenzori Mountains, Kaleveru slopes, 6 kms west of Kilembe, 3 Jun 1970, Katende 345 A (EA); Mahoma, Ruwenzori Mountains 19 Jul 1960, Kendall & Richardson 25 (EA, K); Mount Ruwenzori, below Kanyasabo rock shelter, 3 Jan 1969, Lye, K. 1340 (K); Nyamitaba, R. Mobuku valley, 11 Jul 1952, Osmaston 1549 (BM); Lake Mahoma, Jul 1960, Richardson & Livingstone s.n. (DUKE); Mobuka valley, above Kichundu, 15 Jul 1952, Ross 578 (BM); Ruwenzori, Nyamgasani valley, Jan 1935, Synge 1444 (BM); Toro, Ruwenzori, Namwamba valley, 6 Jan 1935, Taylor 2913 (BM). Bwamba, Ibonde Pass, 1 Oct 1932, Thomas 767 (EA); Nyabitaba Hut, Bujuku Valley below hut, slope down to bridge, 16 Jan 1967, Wood 816 (EA); Ruwenzori E, Mt. Ruwenzori, 21 Feb 1906, Wollaston s.n. (BM).

Madagascar. Antsiranana: vallée du Sambirano, Sep 1909, J. Perrier de la Bâthie 2324 (lectotype, designated here: P [P00352331]; isolectotypes: P [P00352332], MO [MO-150889]).

Liana to 20 m high in canopy. Stems flattened to terete, glabrous or evenly pubescent with dendritic uniseriate trichomes to 0.1 mm long, glabrescent; new growth densely pubescent with dendritic trichomes. Bark of older stems longitudinally ridged, brown to almost white. Sympodial units plurifoliate, the leaves not geminate, somewhat clustered towards tips of branches or on short shoots. Leaves simple, 5–8 (10) cm long, 2.5–4 (5) cm wide, elliptic to obovate, membranous to chartaceous (occasionally thick-chartaceous on older branches), concolorous to weakly discolorous, glabrous with occasional short-branched dendritic trichomes along the midvein or sparsely pubescent on both surfaces with uniseriate dendritic to somewhat echinoid trichomes 0.2–0.5 mm mm long on the veins and lamina, these much denser at the axil of midrib and major veins forming tangled tufts (domatia); major veins 5–7 pairs, spreading at ca. 45° to the midvein and forming loops, the finer venation a prominent network of fine brown veins usually visible on both surfaces in dry material; base attenuate; margins entire; apex acute to acuminate; petiole 1–2(2.5) cm long, glabrous or densely dendritic pubescent with trichomes like those on the stem, pubescence of petiole denser than that of stem. Inflorescences terminal at the apex of short slender lateral branches, 3–6.5 cm long, unbranched or furcate, with 3–10 flowers, usually glabrous, sometimes finely pubescent with dendritic trichomes like those of the stem; peduncle 1–3 cm long; pedicels 1–2.5 cm long, apically dilated, drying ridged, usually glabrous, sometimes evenly pubescent like the rachis, articulated 0–0.5 mm from base; pedicel scars irregularly spaced 1.5–4 mm apart. Buds ellipsoid, the corolla exserted ca. halfway from calyx tube but not exserted beyond the tips of the calyx lobes before anthesis. Flowers 5-merous, apparently all perfect. Calyx tube ca. 2 mm long, an open cup, the lobes 4–10 mm long, 4–8 mm wide at base, uneven in size, deltate, acute at the tips, usually glabrous, sometimes evenly dendritic-pubescent like the rachis. Corolla 2–3.2 cm in diameter, violet or dark purple with a darker midvein, stellate, lobed almost to base, the lobes 10–13 mm long, 3–5 mm wide, ovate to linear, glabrous adaxially, usually glabrous abaxially or sometimes dendritic-pubescent like the rachis, densely papillate on the tips and margins. Stamens equal; filament tube ca. 1 mm; free portion of the filaments ca. 1.5 mm long, glabrous; anthers ca. 3.5 mm long, 1–1.5 mm wide, ellipsoid, not tightly connivent, smooth abaxially, poricidal at the tips, the pores much smaller than anther apices, ca. 0.4 mm in diameter, not lengthening with age. Ovary conical, glabrous; style ca. 9 mm long, protruding ca. 2 mm beyond the anthers, curved, glabrous; stigma capitate, dark, the surface smooth. Fruit an ovoid berry, ca. 0.9 cm long, 0.8 cm in diameter (immature), apically pointed, the pericarp thin, glabrous, drying black, but mature colour not known; fruiting pedicels 2.3–3 cm long, ca. 1 mm diameter at base, spreading, ridged; fruiting calyx lobes strongly accrescent, increasing to 1 cm long, sometimes extending further than the developing fruit, spreading (immature fruit only). Seeds not known from mature fruit.

Figure 23. 

Solanum sambiranense D’Arcy & Rakot. A Flowering branch B Flower bud C Open flower from side showing spreading corolla lobes D Open flower from above, showing terminal anther pores E Fruiting branch F Domatia on leaf abaxial surface at junction of midvein and lateral veins G Immature berry H Dendritic trichome I Simple trichome. (Based on: ARanirison & Nusbaumer 1032; B, CNusbaumer 860; D, ERandrianasolo 580, drawn from photograph; F–IPerrier 2580). Scale bar: A, E = 3 cm; B–D = 1.5 cm; F, G = 1 cm; H, I = 0.3 mm. Drawn by Lucy T. Smith.

(Figure 24). Endemic to northwestern and north-central Madagascar in the provinces of Mahajanga and Antsiranana.

Figure 24. 

Distribution of Solanum sambiranense D’Arcy & Rakot.

Dry to subhumid woodland on limestone; 500–1500 m elevation.

None recorded.

(IUCN 2014). Least Concern (LC). EOO 109,250 km² (LC), AOO 40 km² (EN). In common with other members of the ANS clade in Madagascar, Solanum sambiranense has a relatively wide distribution, resulting in an EOO indicating lack of immediate conservation concern. The paucity of collections, indicative of local rarity, however, coupled with the ongoing habitat threats in Madagascar, does indicate monitoring and further collection to assess local and regional rarity is necessary.

Solanum sambiranense is a large-leaved liana (Figure 2A) with very large showy flowers (Figure 1D) endemic to the northern half of Madagascar. It has long petioles, long attenuate leaf bases, prominent tufts of tangled trichomes in the axils of the midrib and main leaf veins beneath (domatia, see Fig. 23), inflorescences with 3–10 flowers and foliaceous calyx lobes up to 6 mm in flower, often expanding past the developing fruit. Prior to the description of S. sambiranense in 1994 collections of this species were thought to belong to the similarly dendritic-pubescent S. imamense.

Solanum sambiranense is similar to S. imamense and S. betroka and could potentially also be confused with S. ivohibe. Solanum sambiranense can be distinguished from S. imamense by its elliptic to obovate (versus ovate) leaves 5–10 cm (versus 2.5–5 cm) long, and glabrescent leaf surface with dendritic trichomes below 0.1 mm long (versus densely pubescent leaves with indumentum reaching 0.2–0.5 mm in length). The distribution of S. sambiranense and S. imamense overlaps in north-central Madagascar even though S. imamense occupies drier areas further south. Solanum sambiranense differs from S. betroka by its inflorescences with 3–10 (versus 1–3) flowers, calyx lobes 4–6 mm (versus 2–3 mm) long, and leaves 5–10 cm (versus under 5 cm) long with attenuate (versus cuneate to truncate) leaf bases. Solanum sambiranense is morphologically similar to and potentially confusable with S. betroka: both have a clearly visible brown fine venation network, green brown leaves on herbarium specimens, membranous glabrescent leaves without thick indumentum, and a similar habit. Typical representatives of the southern S. betroka and northern S. sambiranense are clearly distinct but specimens from the centre of Madagascar are more difficult to determine; the two species occupy distinct ecological niches with S. betroka restricted to the more arid south. Solanum sambiranense can be distinguished from S. ivohibe by its inflorescences with 3–10 (versus 10–16) flowers, and calyx lobes 4–6 mm long tearing for up to 2 mm (versus calyx lobes 0.8–2 mm long tearing for up to 1mm); S. sambiranense also occurs further north than the only known locality of S. ivohibe in Fianarantsoa.

The distribution of Solanum sambiranense spans northern and northwestern Madagascar, from locations with more dry and seasonal climatic conditions than the wet eastern rainforests, warmer climate than the High Plateau, and more moisture than the south. Larger-leaved forms predominate towards the north and east as habitats get more humid.

D’Arcy and Rakotozafy (1994) state that S. sambiranense differs from other species thought to be related to it by its prominent domatia. These are dense tangled tufts of dendritic trichomes in S. sambiranense; no domatia are seen in S. betroka, but some increased trichome density in the leaf axils has been observed in S. imamense (Baron 1754). All specimens of S. sambiranense have membranous leaves except Perrier de la Bâthie 13022 with membranous leaves on young shoots that become thick chartaceous on main branches. Grevé 241 differs from the typical S. sambiranense by its densely pubescent leaves, but with foliaceous calyx lobes clearly belongs to it.

The protologue cites a holotype from P; of the two duplicates of the type collection held in Paris we here select one of these (P00352331) as the lectotype of S. sambiranense as it bears a note “type collection” in D’Arcy’s handwriting, while the other duplicate of Perrier de la Bâthie 2324 (P00352332) has no additional annotation.

Madagascar. Antsiranana: Ambanja, Sambirano, bassin supérieur du Sambirano, berges du Sambiran, 1937, Humbert 18586 (P); Ambanja, Sambirano, bassin supérieur du Sambirano: forêt de Besanatribe, 1937, Humbert 18709 (P); Antsiranana Rural, Diego-Suarez, a la limite N des collines et plateaux calcaires de l’Ankarana, s.d., Humbert 19072 (MO, P); Ambanja, Tsaratanana, Mont Tsaratanana, 14°01’ S, 48°58’ E Alt: 1000m, 1000 m, Dec 1912, Perrier de la Bâthie, J.M.H.A. 2580 (P); Vohemar, Dairaina, forêt de Binara, a 1370 m du point côté 779, 14 Dec 2005, Ranirison & Nusbaumer 1032 (G, K); canton de Marovato, district d’Ambanja, Réserve naturelle 4 [Tsaratanana], 12 Dec 1953, Réserves Naturelles Madagascar 5766 (MO, NY, P, TAN). Mahajanga: Beanka, partie sud, Kinahango, 23 Nov 2011, Gautier et al. 5707 (G); Tsiampihy, district d’Antsalova, 15 Oct 1932, Léandri 297 (NY, P); Maevatanana, Mahatsinjo, au sud d’Andriba, Feb 1920, Perrier de la Bâthie 13022 (P); Maevatanana, Mahatsinjo, au Nord du Tampoketsa d’Ankazobe, 1000 m, Sep 1926, Perrier de la Bâthie 17783 (P).