Treatment by Isawumi et al. (1996).

Annual or perennial herbs, suffruticose; stems erect or reclining; hairs short-stalked with an erect, elongate apical cell. Leaves alternate, narrowly petiolate; blades chartaceous, ovate to elliptic, serrate, secondary veins pinnate, ascending at 45° angles or more. Inflorescence with single lateral or terminal head or heads in corymbiform groups; peduncles usually solid, sometimes fistulose. Heads with involucres broadly campanulate or hemispherical; bracts 25–100 in 4–8 series, mostly gradate but with outer bracts sometimes elongate and foliiform, tips of bracts appendaged, white or colored; receptacles epaleate. Florets 25–100 in a head; corollas reddish or lavender to white, with long slender basal tube, limb abruptly expanded at base, cylindrical, with lobes about as long as throat, erect, with various hairs and glands outside, inside with cells elongate, transversely striate; anther thecae spurred with small tails; endothecial cells with nodular thickenings on tranverse walls; apical appendages oblong-ovate, rounded or acute at tips, glabrous; nectary elongate, cylindrical; style base without node; sweeping hairs acicular. Achenes cylindrical or turbinate, 8–20-costate, glabrous or with setulae distinctly cleft or with glands or idioblasts, carpopodium annuliform, large to obsolete, with thickened porose walls, raphids in ovules elongate, with rhomboid tips; pappus pluriseriate, persistent or caducous, inner capillary, flattened, barbellate on margins, sometimes shortly connate at base, sometimes with outer row of small scales. Chromosome number x = 10 (Jones 1970, Mathew and Mathew 1983)

Pollen. 43.5–72.0 μm diam. (Isawumi et al. 1996); tricolporate, echinolophate; lacunae regularly disposed, one at each pole, 2 across intercolpus; tectum restricted to muri, with distinct microperforations; stout baculae under muri firmly attached to footlayer (Fig. 3A–I).

Figure 1. 

Photographs of Baccharoides, Bothriocline, and Vernonia potamophila. Baccharoides adoensis (Sch. Bip. ex Walp.) H. Rob. A Habit B Close up of flowering head: note that the corollas are narrowed near the apex and have an lengthened throat that is much longer than the short lobes and the involucral bracts have a differentiated margin that is often pale or reddish; Bothriocline laxa N.E. Br. C Immature heads; Vernonia potamophila Klatt. D Image of herbarium specimen (PRE). See Appendix C for citation details.

Figure 2. 

Illustrations: A Baccharoides adoensis (Sch. Bip. ex Walp.) H. Rob. B Bothriocline aggregata Hutch., note: this taxon is not found in southern Africa C Ethulia conyzoides L.f., note: lack of pappus; and D Gymnanthemum koekemoerae H. Rob. & V. Funk, note: broad involucral bracts without a high midrib. See Appendix C for citation details.

Figure 3. 

Scanning electron electron micrographs from three collections of acetolyzed echinolophate Baccharoides pollen showing variations in spine shape from acute to markedly blunt. A–H. Baccharoides anthelmintica (L.) Moench. A polar view B Equatorial view C Lateral view D Near polar view E Equatorial view F Fractured grain G Lateral view H Equatorial view I Fractured grain. (A–C, USDA P.I. 283729; D–F, Cooray 70031701R; G–I, Koelz 7469). [Views from Robinson and Skvarla (2010); Figure 1 B = original Figure 1G; Figure 1C = original Figure 1H; and Figure 1H = original Figure 1J.]

Most notable secondary metabolites, sesquiterpene elemanolides (Bohlmann and Jakupovic 1990, as Vernonia anthelmintica (L.) Willd., V. hymenolepis A. Rich., V. lasiopus O. Hoffm.), eudesmanolide (Bohlmann and Jakupovi 1990, as Vernonia adoensis Sch. Bip. ex Walp.).

Ivory Coast, Ethiopia, Malawi, Mozambique, Zimbabwe, South Africa.

Congo, Kenya, Tanzania, Uganda, Malawi, Zambia, Zimbabwe, Botswana, Namibia, Sri Lanka, Nepal, Pakistan, India, China.

Angola, also cited from SW Africa, but that locality probably not intended in the restricted sense.

The species is known from photographs of types and from descriptions deposited at US by C.E. Smith. The type photographs – as well as Fig. 1 B (for corollas) – clearly show the corolla form and flattened pappus bristles of Baccharoides, and the species is not accounted for elsewhere. The type specimen of Vernonia benguelensis is collected in Angola, ad lacum de Ivantola, Feb. 1860, Welwitsch 3276b (BM, photo seen). The lectotype of Vernonia limosa is cited as Südwest Afrika, am Longa unterh. Chijija, Jan. 1900, Baum 624 (BM, photo seen; Smith 1917). This locality is situated in Angola (Figueiredo et al. 2009).

Many species are keyed in Jeffrey’s (1988) treatment of Vernonieae in East Africa and in Wild and Pope (1977), Wild (1978a, 1978b).

Perennial herbs (up to 1 m) to subshrubs, branching sparse, stems erect with a solid pith and long-armed T-shaped hairs with short 2-celled stalks. Leaves alternate, opposite or whorled, sessile to short petiolate, blade narrow to ovate or elliptical, pinnately veined, often paler or tomentose to sericeous below. Inflorescence laxly to densely corymbiform or thyrsiform cymes; heads pedunculate. Involucres campanulate, bracts ca. 50–60, gradate in 3–4 series, cuspidate at apex, with distinct pale or reddish lateral margins, nearly glabrous to pilosulous outside; receptacle convex, epaleaceous, with glabrous reticulum. Florets 3–100 or more in a head; corollas purplish, funnelform, basal tube slender with small stipitate glands, throat shorter than 1 mm, lobes, linear-lanceolate, with glandular dots and often with stiff subapical hairs; anther thecae blunt at base with few sterile cells; apical appendages ovate-oblong, with thin cell walls; style base with minimal annuliform node; sweeping hairs acicular, mostly restricted to branches. Achenes prismatic, short and broad with 3–6(–9) ribs, setuliferous with sparse short setulae scarcely split at tips, often densely covered with idioblasts and with scattered subquadrate raphids. Pappus of few or no short easily deciduous bristles narrowed at base, without obvious shorter ourter series or outer pappus a rim or collar. Chromosome number n = 9, 10, 18–20 (Jones 1979, 1982). Pollen grains ca. 47 μm in diam, lophate to rarely sublophate, finely echinate, pores in triplet of connected colpar lacunae, perforated tectum usually restricted to muri (Fig. 4 A–C).

Figure 4. 

Scanning electron micrographs of acetolyzed pollen of echinolophate Bothriocline and Cyanthillium and sublophate-lophate Distephanus. A–C Bothriocline schimperi Oliv. & Hiern ex Benth. A Equatorial view, note incipient colpus of 3 connected lacunae centered on pore B Near polar view C Fractured grain D–F Cyanthillium cinereum (L.) H. Rob. D Equatorial view E Lateral view with apertures on sides F Lateral view G–I Distephanus angustifolia (DC.) H Rob. & B. Kahn. G Polar view H Equatorial view I Lateral view. (A-C, F. Meyer 8159; D-F, Evans 344; G-I, Sidley 2211).

Notable secondary metabolites include 5-alkylcoumarins and sesquiterpene glaucolides/hirsutanolides [Bohlmann and Jakupovic 1990, as Bothriocline laxa N.E. Br., B. longipes (Oliv. & Hiern) N.E. Br.], and Volkesia ripensis Hutch. and 5-alkylcoumarins (Bohlmann and Jakupovic 1990, as Erlangea fusca S. Moore, E. rogersii S. Moore).

Tanzania, Zambia, Malawi, Zimbabwe, Congo, Angola, South Africa (Transvaal).

Traditionally treated as part of Vernonia.

Annual or short-lived perennial herbs to 1 m tall; stems erect or spreading; hairs symetrically or asymetrically T-shaped with short stalk. Leaves alternate; petioles narrow; blades membranaceous, ovate to narrowly lanceolate. Inflorescences terminal, moderately densely to laxly branching, distinctly cymiform or with rather corymbiform branches, with minute bracteoles; peduncles rather short to elongate. Heads narrowly campanulate, involucral bracts ca. 30 in 3(–5) series, gradate, thinly chartaceous, green with pale or purplish margins, persistent, often with pilose to sericeous pubescence; receptacles epaleaceous. Florets 15–94 in a head; corollas bluish to lavender, funnelform with slender lower tubes, throat a third as long to nearly as long as lobes, lobes with simple hairs especially near tips; anthers without tails; apical appendages oblong-ovate, glabrous, with thin cell walls; style base with broad node; style branches with acicular sweeping hairs. Achenes 5-ribbed, or terete, setulae shortly cleft at tips, with idioblasts, sometimes with glands, raphids elongate; inner pappus of many long, sometimes rather fragile, slender-tipped capillary bristles, outer series of persistent squamellae, one species with callose ring. Chromosome number n = 9, 18, 20 (Turner and Lewis 1965, Mathew and Mathew 1976, Jones 1979).

Pollen ca. 30 μm in diameter (dry); triporate, echinolophate, ca. 21 lacunae rather irregularly disposed at poles and in intercolpi; perforated tectum restricted to ridges of muri, with distinct microperforations; spinules of muri short, shorter than width of mural ridge, pointed, without columellae under each murus; baculae single at junctures of muri and no baculae between junctures, each intersection of muri with stout columella that is firmly attached to footlayer (Fig. 4 D–F).

Figure 5. 

Photographs of Cyanthillium cinereum (L.) H. Rob: A Inflorescence, B habit, C Close up of heads in fruit. See Appendix C for citation details.

Notable secondary metabolites, 5-alkylcoumarins, sesquiterpene glaucolides, guanolides (Bohlamnn and Jakupovic 1990, as Vernonia chinensis Less., V. cinerea Less.).

Widely introduced weed, pantropical.

Tropical Africa south to Angola.

Tropical Africa from Congo, Uganda and Kenya south to Zambia, Zimbabwe and South Africa (Transvaal), Madagascar.

Abyssinia, Malawi, Sudan, Swaziland, Tanzania, South Africa (Transvaal), Uganda, Zimbabwe.

For discussion and numerous transfers of species see treatment by Robinson and Kahn (1986). For a recent treatment of the genus in southern Africa see Swelankomo and Manning (2014).

Shrubs or vines; hairs arachnoid, contorted or asymmetrically T-shaped. Leaves alternate; petioles short; blades ovate to rounded, often with truncate to subcordate bases, less often narrow with cuneate bases, margins usually entire or subentire, venation usually with stronger more ascending basal pair or strongly triplinervate, less often irregularly pinnate. Inflorescences terminal on stems or branches, with single heads or usually branching, corymbiform with minute bracts or thyrsoid with foliose bracts; peduncles usually short. Heads with campanulate involucres; bracts 21–24(–75) in 4–6(–7) gradate series, without appendaged tips; receptacles epaleaceous. Florets 10–16(–75) in a head; corollas usually yellow, purplish in a few continental African species; anther thecae with distinct broad often sclerified basal appendages; endothecial cells with simple, broad, non-contiguous, sclerified shields; apical appendages without glands; style base with large abruptly distinct node; style branches with obtuse sweeping hairs. Achenes cylindrical to prismatic, sometimes subtriquetrous or quadrangular, with 5–12 ribs, usually 10, setulae or glands present or absent, raphids elongate; carpopodium turbinate; pappus of many capillary bristles, outer series of squamellae. Chromosome numbers n = 9, 10, 15 (Jones 1982, Gill and Omoigui 1992).

Pollen: 30–36 μm in diameter (dry); tricolporate, sublophate to lophate; lophate forms with muri projecting as spurs into colpus, with echinate or with nearly psilate ridges; tectum continuous in intercolpi and at poles, or in pockets surrounded by ridges, with distinct perforations; with columellae under spines or with muri granular inside, without distinct baculae (Figs 4 G–I).

Figure 6. 

Photographs of Distephanus: A–F Distephanus divaricatus (Steetz) H. Rob. & B.Kahn; G–H Distephanus anisochaetoides (Sond.) H. Rob. & B.Kahn. Note the variable flower color in D. divaricatus. Note: trinervate veination, lack of lavender corollas and presence of yellow and orange. See Appendix C for citation details.

Notable secondary metabolites: sesquiterenes, elemanolides (Bohlmann and Jakupovic, as Gongrothamnus aurantiaca N.E. Br.), guaianolide (as Gongrothamnus sublutea Elliot., guaianolides (Bohlmann and Jakupovic 1990, as Vernonia anisochaetoides Sond., glaucolides/hirsutanolides (Bohlmann and Jakupovic 1990, as Vernonia angulifolia DC., V. tufrnellae S. Moore).

Angola, Namibia.

Jeffrey (1988) mentioned Vernonia biafrae Oliv. & Hiern in Oliv. was once placed in the synonymy of this species by Maquet in Troupin (1985), but cited a number of differences that did not include the strictly pinnate venation of the more northern V. biafrae [= Distephanus biafrae (Oliv. & Hiern in Oliv.) H. Rob.].

Mozambique, South Africa (Natal, Transkei).

South Africa (Cape colony, Natal).

Angola, Botswana, Congo, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Tanzania, South Africa (Transvaal), Zambia, and Zimbabwe.

Mozambique and South Africa (Natal).

Species treatment based on Wild and Pope 1977.

Annual or short-lived perennial herbs; stems erect, branching near base; hairs on vegetative parts simple, uniseriate, multicellular, with a straight elongate apical cell. Leaves alternate, sessile or subsessile, pinnately veined with weak secondary veins, margins serrulate, apices obtuse. Inflorescence with single terminal head or laxly cymiform with narrowly pedunculate heads. Heads campanulate; involucral bracts 45–60 in 3–4 series, gradate, cuspidate apically, with distinct pale or reddish lateral margins, pilose to lanulose outside; receptacle convex, epaleaceous, with glabrous reticulum. Florets 50–75 or more in a head; corollas reddish, funnelform, with slender basal tube bearing small stipitate glands, throat shorter than lobes, lobes linear-lanceolate, with stiff hairs distally or apically; anther thecae short-acute with small sterile margin at base; apical appendage, oblong-ovate, glabrous, with thin cell walls; style base with narrow annuliform sclerified node; sweeping hairs acicular, at lowest level scarcely extending to top of shaft. Achenes shortly obconic, abruptly narrowed distally to insertion of corolla, 3-6-ribbed, setulae restricted mostly to broad ribs, setulae not split at tips, sides with scattered isolated idioblasts, raphids subquadrate or short oblong in dense inner layer of short to quadrate cells in achene wall; pappus of less than 20 easily deciduous barbellate bristles, bases narrow and weakly attached, distinct outer series not evident. Chromosome number n = 10 (Turner and Lewis 1965, Nordenstam 1967).

Pollen ca. 47 μm in diameter in fluid, lophate, triporate, with group of polar lacunae, perforated tectum restricted to muri, bacculae centered at junctures of muri, leaving ogee-shaped gaps under the centers of the muri (Figs 8 A–C).

Figure 7. 

Photographs of Erlangea and Ethulia: A–B Erlangea misera S. Moore, and C–EEthulia conyzoides L.f. subsp. conyzoides, note: Ethulia has no capillary pappus. See Appendix C for citation details.

Figure 8. 

Scanning electron micrographs of acetolyzed echinolophate pollen of Erlangea and sublophate pollen of Ethulia. A–C Erlangea misera (Oliv. & Hiern) S. Moore. A Poral view B Near polar view C Grain fragment. D–F Ethulia conzyoides L.f. D Equatorial view, showing comparatively blunt spines E Lateral view F Grain fragment. (D–F Funk 12708 GPetelot 4047HLewis 6025; Ethulia views from Robinson and Skvarla (2010)).

Notable secondary metabolites, eudesmanolide sesquiterpene lactones, Bohlmann and Jakupovic 1990, as Erlangea remifolia Wild & Pope).

Botswana, Mozambique, Namibia (Caprivi strip), Zambia, Zimbabwe.

Botswana.

Treatment of the genus by Gilbert and Jeffrey (1988).

Annual or short-lived perennial herbs, rarely rhizomatous; stems terete and usually striate, with broad solid pith; hairs uniseriate with erect apical cells, with glandular dots. Leaves alternate, sessile or short petiolate; blades thinly herbaceous, ovate to linear lanceolate, base cuneate or continuous onto stem, margins subentire to serrate or dentate, apex acute to obtuse, surfaces glabrous to densely pubescent; venation pinnate with ascending secondary veins. Inflorescence terminal, corymbiform to rather cymiform, lower bracteoles a reduced foliiform, peduncular bracteoles filiform. Heads rather small, with broadly campanulate involucres; involucral bracts 15–40 in 2–3 usually subequal series; receptacle flat or slightly convex, epaleaceous. Florets 3–100 in a head, strongly exserted; corollas white or pink to purple, with glandular dots on surface, with a narrow cylindrical base, limb narrowly funnelform to narrowly campanulate; lobes lanceolate, without apical hairs; bases of anther thecae rounded, not tailed; apical appendages glabrous; style base without node; branches with sweeping hairs shortly acute. Achenes cylindrical with 2–6 usually paler ribs, sides with glandular dots, rarely with short white setulae; raphids short-oblong; pappus lacking or a coroniform rim. Chromosome number n = 10, 20 (Pilz 1980; Gilbert and Jeffrey 1988).

Pollen: ca. 35 μm in diam. in fluid; tricolporate, sublophate, echinate, spines long; tectum continuous in intercolpi and at poles, distinctly microperforate; columellae below spines firmly attached to footlayer (Fig. 8 D–F).

Notable secondary metabolites: 5-alkylcoumarins (Bohlmann and Jakupovic 1990, as Ethulia conyzoides).

Tropical and southern Africa, Asia to China, introduced in Brazil.

Shrubs or small trees, moderately to densely branching; stems mostly terete, with solid pith; hairs of stem often forming a felt, with large often contorted cap cells basally or nearly basally attached. Leaves alternate; petioles short, winged or elongate; blades membranaceous to rather coriaceous, margins entire to serrate or repand dentate, upper surfaces essentially glabrous and somewhat glossy to arachnoid tomentose; secondary veins pinnate, spreading at 30–80° angles, arching nearer margins. Inflorescences terminal, densely corymbiform, with small bracteoles; peduncles short. Heads with campanulate to cylindrical or ovoid involucres; involucral bracts coriaceous to subcoriaceous, appressed, 25–35 in 4–5 gradate series, inner bracts persistent to easily deciduous, outer surface with smooth median shield, without narrow median costa or keel; receptacles epaleaceous. Florets 5–50 in a head; corollas white to violet, basal tube cylindrical, throat longer than the anther thecae or very deeply cut, lobes with glands or spicules on outer surface; anther thecae with base broadly tailed, tails often long; apical appendages glabrous, with rather thick-walled cells; style base without or with scarcely distinct node; style branches with stout, pointed sweeping hairs. Achenes 5–10-costate, with or without setulae, raphids short to elongate, sometimes not evident; pappus of many rather persistent capillary bristles, often with broadened tips, with outer series of short squamellae. Chromosome numbers n = 10, 15, 20 (Jones 1970, 1982; Adegbite and Ayodele 2004).

Pollen: 30–35 μm in diam. (dry); tricolporate, echinate, sublophate; tectum continuous in intercolpi and at poles, with distinct microperforations; spines long, each with single stout columella below firmly attached to footlayer, intervening perforated tectum scarcely mamillose on inner surface (Fig. 10 A–E).

Figure 9. 

Photographs of Gymnanthemum: A Gymnanthemum corymbosum (Thunb.) H. Rob. B–D Gymnanthemum capense (A. Spreng.) J. C. Manning & N. Swelankomo. See Appendix C for citation details.

Figure 10. 

Scanning electron micrographs of acetolyzed pollen of two collections of sublophate echinolophate Gymnanthemum capense (A. Spreng.) J. C. Manning & N. Swelankomo. A Polar view B Equatorial view C Lateral view D Fractured grain structure of exine surfaces E Fractured grain showing spine construction. (A–CSchlechter 6644).

Generic limits more restricted than given in Robinson (1999a), see Robinson and Skvarla (2006, 2007) and Robinson et al. (2008).

A special effort has been made to resolve the endemic southern African element of Gymnanthemum that includes G. corymbosum and G. capense (Swelankomo et al. 2015).

The species is used as medicinal plant by both people and animals.

Africa and introduced into Brazil.

Transvaal, Natal, Swaziland, Cape colony.

Swelankomo et al. (2015) point out that the older name Eupatorium capense should have been used for this species, and they make the necessary new combination. The combination Vernonia capensis has been used since 1917 for another species (now in Hilliardiella). At this time there is still no unpreoccupied name for the species that has been called V. mespilifolia in the genus Vernonia. Two specimens examined: Rogers 28651 from Grahamstown, and C.E. Smith & Duthie 4678 from Natal, the latter originally distributed as Vernonia crataegifolia.

Tropical and subtropical Africa.

Eastern South Africa through Swaziland and Natal, Transkei, s. Mosambique.

Many specimens from South Africa been seen including Schlechter 6644 distributed under the name Vernonia angulifera DC., nom. nud.

South Africa (Transvaal, Natal, Swaziland, Cape colony).

The species is known in this study from descriptions, from photographs of the syntype, Clydesdale, Tyson 1188 (K) deposited at the US by Earl Smith, and one specimen, Sidey 3470 from Natal, distributed originally as Vernonia corymbosa.

Holotype: South Africa. Limpopo Province: Thohoyandou District; Thathe-Vonde Nature Reserve. Grassland at rocky outcrop near entrance, 1233 m, 22°55'10"S, 30°19’36”E [2230CD], 23 March 2002, Koekemoer 2273 (PRE, isotype US) (Fig. 2D).

The type specimen was distributed as Vernonia triflora Brem., which differs by having only 3 florets in its capitula, stiffly and densely hispid stems, and ovate to oblong leaf blades with hispidulous abaxial surfaces.

South Africa

West Africa from Guinea and Sierra Leone to Cameroon, Sudan, Ethiopia, Kenya, Uganda, Congo, south to South Africa (Transvaal, Natal), and Swaziland.

Congo and Nigeria east to Uganda, Kenya, Ethiopia, and south to South Africa.

South Africa (Transvaal).

One specimen has been seen, Stalmans 2430AA, from South Africa (Transvaal), that matched the original description in every respect except for the lack of noticeable pubescence on the involucral bracts.

Herbaceous perennials to 1 m tall; stems pilose, hairs unequally T-shaped. Leaves alternate; blades abaxially often densely canescent pilose. Inflorescence laxly to subdensely corymbiform-cymose. Heads short-pedunculate; involucres campanulate, bracts 25–40, in ca. 3–4 series, persistent; receptacle epaleaceous. Florets 12–20 in a head; corollas purple, outside with few to many slightly contorted T-shaped hairs; basal tube funneliform above, throat short, lobes linear; anther thecae not or shortly appendaged at base; apical appendages glabrous, with thin walls; style with basal node; style branches with acicular sweeping hairs. Achenes 4–5-costate, densely setuliferous, setulae scarcely divided at tips, idioblasts numerous, raphids elongate, carpopodia narrowly cylindrical; pappus bristles white, barbate, tenuous, subpersistent, outer series shortly lanceolate. Chromosome number of n = 9, 10, most reports n = 10 (Turner and Lewis 1965; Jones 1982).

Pollen grains sublophate, with continuous perforated tectum between colpi, tricolporate to poles, echinate (Fig. 14 A–H).

Figure 11. 

Photographs of Hilliardiella. A–B Hilliardiella aristata (DC.) H. Rob. C–D Hilliardiella flanaganii (E. Phillips) H. Rob. See Appendix C for citation details.

Figure 12. 

Photographs of Hilliardiella oligocephala (DC.) H. Rob.: A Habit B Close up of head C Characteristic leaf D heads in fruit. Note: discolorous leaves are characteristic of some but not all species of Hilliardiella. See Appendix C for citation details.

Figure 13. 

Illustrations Hilliardiella, Linzia, Parapolydora, and Vernonella: A Hilliardiella capensis (Houtt.) H. Rob., Skvarla & V.A. Funk B Linzia glabra Steetz in Peters, note: characteristic teeth on involucral bracts C Parapolydora gerrardii (Harv.) H. Rob D Vernonella africana Sond. See Appendix C for citation details.

Figure 14. 

Scanning electron micrographs of acetolyzed pollen from two collections of Hilliardiella capensis emphasizing spine variations. The surface seems to vary between sublophate and slightly echinolophate. A Polar view B Equatorial view C Lateral view D Polar view E Equatorial view F Subpolar view G Fragmented pollen surface H Grain fragment showing structural support of spine. (A–CBayliss BS3686D–HGentry & Barolas 18914).

Notable secondary metabolites; acetones & sesquiterpene glaucolides/ hirsutanolides (Bohlmann and Jakupovic (1990, as Vernonia sutherlandii Harv., guaianolides, bisabolene derivatives (Bohlmann and Jakupovic 1990, as V. hirsuta Sch. Bip. ex Walp. and V. oligocephala (DC.) Sch. Bip. ex Walp.).

Lesotho, South Africa (Transvaal, Orange Free State, Natal, Cape colony), and Swaziland.

Lesotho, South Africa (Transvaal, Orange Free State, Natal, Cape colony) and Swaziland.

This complete synonymy shows that the oldest name for the species is Erigeron capensis Houtt.

Distinguished as a variety from typical Vernonia hirsuta DC. by Phillips (1925) by the narrow, not cordate, bases of the lower leaves and the long-acuminate tips of the involucral bracts that equal or exceed the pappus.

South Africa (Natal).

Lesotho, South Africa (Transvaal, Orange Free State, Natal, Cape colony), and Swaziland.

South Africa (Cape colony, Natal, Transvaal).

Tanzania south to South Africa (Transvaal, Orange Free State, Natal, Cape colony), Botswana, Lesotho and Swaziland.

Mozambique, South Africa (Transvaal), and Swaziland.

South Africa (Natal, Transvaal) and Swaziland.

Perennial herbs; stems with simple multiseptate hairs. Leaves alternate, subsessile to short-petiolate. Inflorescence corymbiform cymes or single heads with short to long peduncles. Involucre funnelform to campanulate; bracts 50–150 in 5–6 series, often pectinate-denticulate with spicules along lateral margins, outer tips often elongate, green and recurved; receptacle epaleaceous. Florets ca. 20–50 in a head; cortollas bluish, tube very long, funnelform near throat; throat very short, lobes apically stiffly pilosulous; anther base rounded; apical appendage glabrous, triangular with thickened ornamentation in center; style base with small annuliform node. Achenes strongly 10-costate, usually with rows of idioblasts or specialized cells along sides of costae, surface setuliferous, setulae slender with pairs of cells not or scarcely separated at tip, raphids subquadrate to short-oblong; pappus of many somewhat persistent long bristles, with outer series short. Chromosome number n = 10 (Jones 1979, 1982).

Pollen tricolporate, psilolophate, with spur muri intruding into short colpi above and below pore, single polar lacunae often present, not echinate, with or without micropunctations resticted to muri. Muri showing baculae with broadened base, branching distally into many bacula-like branches (Fig. 16 E), a form that seems almost transitional to a rhizomate condition.

Most notable secondary metabolites, sesquiterpene germacranolides, elemanolides (Bohlman and Jakupoic 1990, as V. glabra Vatke & V. melleri Oliv. & Hiern).

Figure 15. 

Photographs of Linzia and Namibithamnus: A–BLinzia glabra Steetz in Peters, note that the flowers bloom in two groups with the outer ones blooming first (light colored in 15B) followed by the innermost ones (dark purple in 15B) C–D Namibithamnus obionifolius (O. Hoffm.) H. Rob. See Appendix C for citation details.

Figure 16. 

Scanning electron micrographs of Linzia and Namibithamnus pollen. A, B, E Linzia rosenii. (R.E. Fries) H. Rob., Skvarla & V.A. Funk. A Polar view B Equatorial view C Equatorial view. Note differences of lophae surrounding pores in B and C, D Linzia glabra Steetz in Peters. Lateral view. E Linzia rosenii. Fractured pollen wall. F–H Namibithamnus obionifolius (O. Hoffm.) H. Rob., Skvarla & V.A. Funk. F Equatorial view. This is the most common form of aperture G Equatorial view. Less common form of aperture with broken lophal arms apparent H Near polar view (A–C, EJacobsen 3075DWest 7292F-HTölken & Hardy 770).

Angola, Burundi, Cameroon, Congo, Malawi, Nigeria, Sudan, Tanzania, Uganda, Zambia, Zimbabwe.

Burundi, Congo, Kenya, Tanzania, Madagascar, south to Angola, Mozambique, and Namibia, South Africa (Transvaal, Natal) and Swaziland.

Botswana.

Vernonia obionifolia O. Hoffm.

Small aromatic shrubs to 1.5 m tall; stems, leaves, involucral bracts densely yellowish gray tomentellous or sericeous with crowded T-shaped hairs, hairs with slender 0–2-septate short stalks and small naviculiform or rather elongate cap-cells. Leaves alternate, short-petiolate, with small axillary fascicles usually present, more crowded proximally, smaller distally; blades 5–12 mm long, oblong to obovate, with undulate entire to coarsely dentate margins, basal pair of secondary veins scarcely evident or evident and strongly ascending, minute glandular dots densely disposed on both surfaces. Inflorescences appearing shortly scapose, with numerous pedunculate heads in a corymbiform or partly subumbellate arrangement. Heads campanulate, 6–7 mm wide and high; involucral bracts ca. 60 in ca. 6 strongly gradate series, persistent, oblong ovate with narrow apiculate tips, yellowish with reddish patch or midvein below tip, margins entire, broadly and distinctly thick and pale; receptacle convex, pitted with broad pale network of ridges. Florets 35–40 in a head. Corollas purple, narrowly funnel-shaped from a slender basal tube; throat twice as long as the erect, linear lobes, outer surface of base and throat mostly glabrous, lobes densely glandular-dotted; anther thecae narrow, slightly longer than throat, bases without tails, apical appendages shortly oblong-triangular, glabrous, with thin cell walls; style base with narrow annuliform node; with acicular sweeping hairs almost completely restricted to style branches, a few at top of shaft. Achenes 5-costate, with setulae not divided at tips, surfaces with numerous ungrouped idioblasts, raphids elongate; carpopodium turbinate, glabrous; pappus of ca. 35 slender persistent bristles, bristles as wide at tips as at base, densely scabrid on margins and outer surface, outer series of distinct, smooth, lanceolate scales. Chromosome number unknown.

Pollen ca. 45 μm in diam. in fluid, lophate, triporate, not echinate, perforated tectum restricted or lacking, crests of muri sparsely papillose (Fig. 16 F–H).

With habit remarkably like Orbivestus cinerascens, and often in herbaria identified as this species. Differs clearly by non-seriate cymose inflorescence, thicker pale margins on involucral bracts, thicker tips on pappus bristles and lophate/triporate pollen. The margins of the involucral bracts are similar to those of Erlangea and Bothriocline.

Namibia.

Thoroughly distinct in appearence, having larger more lobed leaves indicative of more moist habitats.

Namibia.

Low, much-branched shrubs to 1 m high, stems with L-shaped hairs on multiseptate stalks, cap-cells one-armed. Leaves alternate, sub-sessile, linear to elliptical, sometimes serrate. Inflorescences corymbiform cymes, with usually shortly pedunculate heads or with heads sessile in apical clusters of leaves. Involucre ovoid or cylindrical; bracts 20–40 in 4–7 gradate series, ovate to oblong, appressed; receptacle without pales. Florets ca. 10–15 in a head; corollas white or lavender, tubular to narrowly funnelform, throat as long as lobes, tips without hairs or with few short biseriate hairs; anther bases rounded, apical appendages glabrous, with thin-walled cells; style base with narrow ring; style branches with acicular sweeping hairs. Achenes weakly 8-ribbed, sericeous with many setulae, idioblasts numerous, raphids narrowly elongate; pappus biseriate, outer shorter and broader, inner setiform, subplumose, glabrous near base. Chromosome number unknown.

Pollen 7–8-porate, with pores scattered over the whole surface in lacunae that are usually not adjacent, lophate (Fig. 18 A–F), minutely papillose on muri, nonperforated tectum restricted to muri, emicropunctate, baculae regularly spaced in single row under muri or lophae, baculae subtended by “rhizomate” structure that is as broad as the outer layer, and gives the muri or lophae a two-layed structure with small evenly spaced columellae separating the layers. The rhizomiform base of the muri is weakly attached to the footlayer thus causing muri to easily detach from the core of the grain. Lacunae of exine of pentagons mixed with hexagons. The structure of the bucky ball was a remarkable close approximation of the structure of the pollen. It was study of the toy ball that led to the conclusion that the pollen characteristically had seven or eight pores. Other pollen grains show a somewhat different pattern of pores, where pores occur in pairs, one each in a pair of adjacent lacunae (Fig. 18 B). The polyporate, subspherically symmetrical, rhizomate form of pollen in Oocephala is shared in a somewhat less symmetrical form by Polydora, but as far is currently known, these Oocephala and Polydora grains, with their non-equatorial pores, are unique in the Asteraceae (Robinson and Skvarla 2014).

Figure 17. 

Photographs of Oocephala and Orbivestus: A–B Oocephala centauroides (Klatt) H. Rob. & Skvarla, note: egg-shaped head C–E Orbivestus cinerascens (Sch. Bip. in Schweinf.) H. Rob. See Appendix C for citation details.

Figure 18. 

Scanning electron micrographs of Oocephala staehelinoides (Harv.) H. Rob. & Skvarla. A Unacetylized grain showing three pores with caps intact, two pores in adjacent lacunae B–D Intact or nearly intact grains showing pores in both pentagonal and hexagonal lacunae B with pores in adjacent lacunae E Grain stripped of muri showing five pores and stubs of muri attachments F Segment of muri showing rhizomate structure and remnants of weak basal attachments to footlayer, (p) pore. A–F are from collection of Liebenberg 8843.

Notable secondary metabolites: sesquiterpene glaucolides (Bohlmann and Jakupovic 1990 as Vernonia staeheleinoides Harv.).

South Africa (Transvaal, Natal), and Swaziland.

South Africa (Transvaal), and Swaziland.

Subshrubs to small shrubs with erect stems from a woody base, not or sparsely branched between base and inflorescence; hairs T-shaped. Leaves alternate, usually decrescent upwardly, sessile or short petiolate, blades elliptical or ovate to oblanceolate, mostly 4–9 cm long, 2–5 cm wide, base short-obtuse to acuminate, margins scarcely repand-dentate, apex short-acute, upper surface with small spinules and few small hairs, lower surface paler, grayish with slender hairs and partially sunken glandular dots; venation pinnate, with up to six or eight lateral veins each side, spreading at 45–60º angles. Inflorescences with leaves of main axis only somewhat to greatly reduced, with only minute bracteoles on branches. Inflorescence shape broadly corymbiform or cylindrical with rounded to flattened top, with lower heads appearing sessile as result of proliferation by immediately subtending branches forming seriate or scorpioid cymes, branches of inflorescence tomentose with T-shaped hairs. Heads broadly campanulate, 4–14 mm high and wide; involucral bracts mostly persistent, innermost somewhat deciduous, ca. 50–100 in 5–7 series, strongly gradate, 1–8 mm long, 1.0–1.5 mm wide, ovate to oblong, subacute and mucronate to apiculate at tip, innermost acute, tips appressed, margins membraneous and irregularly denticulate distally, often reddish, with dark median keel extending to apex, scarcely thickened and greenish near keel, with numerous small T-shaped hairs except at margins. Receptacle epaleate and tuberculate. Florets 15–ca. 50 in a head; corollas purplish, narrowly funnelform, 4–8 mm long, with sparsely scattered glandular dots, tube slender, 2–3 mm long, throat 1.5–2.5 mm long, lobes 1.0–2.5 mm long, linear-lanceolate, erect, not recurving, sparsely glanduliferous to distinctly or minutely scabridulous outside, without longitudinal internal ducts filling lobe; anther thecae 1–2 mm long, without glandular dots, calcarate and with long tails at base, endothecial cells short usually with 2–3 nodes on transverse walls; apical appendage 0.5–1.0 mm long, narrowly lanceolate, often sharply acute; style base with distinct expanded node; sweeping hairs on style branches and scarcely extending on to upper style shaft, slender and narrowly acute. Achenes 1.5–2.0 mm long when mature, 5-costate, with few to many setulae when young, often glabrous at maturity, often with numerous glandular dots on sides between costae, surface with numerous idioblasts that are not joined in series, with narrowly rhomboid raphids internally; carpopodium stopper-shaped to slightly turbinate, with many series of small thick-walled cells; inner pappus of 25–30 slender capillary bristles, rather flattened outside and barbellate on sides, tips only slightly narrowed, outer pappus of narrow scales 0.5–1.5 mm long. Chromosome numbers n = 10, 18, 20 (Mangenot and Mangenot 1962; Bhandari and Singhvi 1977; Morton 1993).

Pollen grains ca. 50 μm in diameter in fluid, type A, sublophate, tricolporate, echinate, with perforated tectum continuous between colpi (Fig. 19 D–E). The grains may also be somewhat asymmetrical (Fig. 19 A).

Figure 19. 

Scanning electron micrographs of Orvibestus cinerascens (Sch. Bip. in Schweinf.) H. Rob. A Polar view showing 3 colpi B Polar view showing 4 colpi C Lateral view showing highly perforated sheet-like layers of exine common in many grains of the sample D Equatorial view (appearing nearly echinolophate) E Lateral/equatorial view showing 2 pores F Fractured grain showing thickened columellae supporting a higher perforate surface G Fractured polar surface (A–GKoekemoer 232).

Most notable secondary metabolites are 5-alkylcomumarins (Bohlmann and Jakupovic 1990, as Vernoniia cinarescens Sch. Bip.) and sesquiterpene glaucolides (Bohlmann and Jakupovic 1990, as Vernonia cistifolia O. Hoffm.).

The genus is almost alone in the eastern hemisphere in its seriate cymes, often referred to as scorpioid cymes. Such inflorescences are common in the western hemisphere Vernonieae, occurring in Vernonia itself.

Perennial herbs 0.2–1.0 m tall; from slender prostrate or creeping stem or rhizome, erect stems with few to many ascending branches, five-ribbed, sides with numerous glandular dots, glabrous or finely and sparsely puberulous with some simple multiseptate hairs, and some one-armed L-shaped hairs with stalk near one end as in Polydora. Leaves alternate, linear to narrowly elliptic-lanceolate, venation pinnate with short, ascending, secondary veins weakly prominulous below, surfaces concolorous, glandular dots more numerous below, sparsely puberulous. Inflorescences of long-pedunculate heads terminal on leafy stems and branches; involucres broadly campanulate to subglobose; involucral bracts 110–130 in ca. six series, persistent, gradate, from 2–12 mm long, bases of bracts oblong, pale, appressed, covered with dense pale tomentum, bracts distally constricted into long glabrous, often reflexed awn, darkened along costa near base of awn; receptacle epaleaceous, alveolate. Florets 45–50 in a head; corollas lavender, without hairs, basal tubes narrowly funnelform, glabrous, throats about as long as linear lobes, few glands on throat and glands clustered at lobe tips; thecae of anthers without tails at base; apical appendages ovate-lanceolate, glabrous, with thin-walled cells; style base with distinct annular node; style branches with long acicular sweeping hairs scarcely extending below base of branches. Achenes weakly 8–10-veined, with setulae becoming long and uniseriate from near middle or near base, rarely with one long cell and one short cell, idioblasts numerous from base to top of achene, raphids elongate; pappus white or grayish, inner series of many barbellate bristles, not broadened at tips, outer series of numerous, short, linear scales. Chromosome number unknown.

Pollen ca. 50 μm in diam., sublophate, echinate (Type A), tricolporate, sub-echinolophate (Fig. 21 A–D).

Most notable secondary metabolites, sesquiterpene nerolidol derivatives (Bohlmann and Jakupovic (1990).

Figure 20. 

Photographs of Parapolydora and Polydora: A–C Parapolydora fastigiata (Oliv. & Hiern in Oliv.) H. Rob. D–F Polydora poskeana (Vatke & Hildebrandt) H. Rob. See Appendix C for citation details.

Figure 21. 

Scanning electron micrographs of acetolyzed sublophate-echinolophate pollen grains of two collections of Parapolydora fastigata (Oliv. & Hiern in Oliv.) H. Rob. A Polar view B Equatorial view showing thickened echinolophate ridges along aperture C–D Lateral views showing highly perforate meandering lophal ridges E Grain fragment showing thickened columellae underneath two spine regions F Grain fragment showing perforate lacunar exine with close parallel proximity to foot layer between thickened columellae supporting spines. (APienaar 1073B–FSeydel 4023).

Namibia, South Africa (Transvaal), and Zimbabwe.

South Africa (Natal).

Some species of the genus are treated by Pope (1986).

Mostly annuals; stems with L-shaped hairs bearing elongate one-armed cap-cells. Leaves alternate. Inflorescence a thyrsoid panicle with corymbiform cymose branches bearing pedunculate heads or a single terminal head. Involucral bracts ca. 80 in ca, seven series, often with widely scarious margins and awns often black at tips; receptacles epaleaceous. Florets ca. 30 in a head; corollas whitish to purplish, basal tube long, narrowly funnelform distally, throat as long as the narrow glabrous lobes; anther bases plain, not tailed; apical appendage glabrous, with thin cell walls, sometimes weakly ornamented; style base with distinct annular node; branches with acicular sweeping hairs. Achenes 5 or 8–10-ribbed, setuliferous with setulae scarcely divided at tips, idioblasts present but not grouped, raphids elongate; pappus with copious barbellate setae, greenish, yellowish or tawny, rarely white, outer pappus short, squamiform. Chromosome number n = 9, 10 (Jones 1979, 1982, Ayodele 1999).

Pollen lophate with ca. 32 lacunae, with five or more pores that seem to be rather asymmetrically distributed on the grains; the pores occur in lacunae that, in a few cases, are adjacent; margins of muri minutely echinate to psilate, without micropunctations, baculae closely spaced in single evenly spaced row under each murus, baculae in turn subtended by “rhizomate” structure that is weakly attached to the footlayer, the muri thus easily stripping away from the footlayer (Fig. 22 C). The pollen of Polydora proves to have a lophate condition with well-defined lophae or muro bearing 4–5 spinules on each segment. The lophae are subtended by columellae in a single series not leaving an ogee-shaped gap in the middle.

Notable secondary metabolites: sesquiterpene lactone glaucolides/hirsutanolies (Bohlmann and Jakupovic 1990, as Vernonia poskeana Vatke & Hildebr.), elemanolides, eudesmanolides, secoglaucolides (Herz 1996, as Vernonia poskeana Vatke & Hildebr.

Figure 22. 

Scanning electron micrographs of Polydora angustifolia (Steetz) H, Rob. A Intact grain with visible pore B Intact grain with 2 visible pores in adjacent lacunae C Grain with muri partially removed showing distorted inner surface and five pores, one pore on opposite surface visible through torn area. A from Brass 16090B, C from Christensen & Patel 1457. Views from Robinson & Skvarla, PhytoKeys 2014.

Polydora angustifolia is the species with which Steetz first introduced the use of pollen structure in the taxonomy of the Asteraceae (Steetz in Peters 1864). The generic name Crystalopollen was based on the lophate pattern of the pollen observed by Steetz.

Tanzania, Mozambique and Natal east to Malawi, Zambia and Zimbabwe.

Angola, Botswana, Namibia, South Africa (Transvaal), and Zimbabwe.

South Africa (Transvaal), Swaziland.

Pegolettia tenella DC.

Small perennial herbs; stems erect, with short branchlets from lower nodes, puberulous to subsericeous with short-stalked hairs bearing asymmetric cap cells, stalks moderately broad with one or two septae, cap cells short and stout, attached near lower end. Leaves alternate, oblong to linear, essentially sessile, sparsely puberulous, abaxially densely glandular punctate. Inflorescence terminal with 1 or a few heads borne on long peduncles. Heads campanulate, 1.7–2.5 cm. wide; involucral bracts 20–60, in ca. three series, subequal, linear-lanceolate, herbaceous with slender tips, pilosulous outside; receptacle slightly convex, surface with angular thickenings. Florets 15 or more in a head; corollas purple, ca. 1 cm long, narrowly funnel-shaped from a slender base, throat slightly shorter than the moderately distorted, linear-lanceolate lobes, outer surface with short glands on tube and throat, spiculiferous distally on lobes; anther thecae narrowed at base to short lobulate tail; apical appendage glabrous, ovate with rather firm cell walls; style base with narrow annular node; sweeping hairs acicular, restricted mostly to style branches, few on upper shaft. Achenes mostly 6–8-ribbed, to 4.5 mm long, with glandular punctations and scattered idioblasts on sides, rarely without or with many short setulae that are not or scarcely split at apex, inner layer without raphids or with subquadrate raphids, with layer of rather sclerified narrow cells appearing as striations under the glands and idioblasts; carpopodium broadly stopper-shaped, sometimes with few short uniseriate hairs on inner surface; pappus of ca. 40 scabrid bristles, mostly in one series, as long as tube and throat of corolla, rather easily deciduous, scarcely narrowed except at tips, with few indistinct short bristles in outer series. Chromosome number unknown.

Pollen ca. 47 μm in diam., tricolporate, sublophate, echinate, with perforated tectum continuous between colpi (Fig. 24 A–H).

Figure 23. 

Photographs of Pseudopegolettia and Vernoniastrum: A–C Pseudopegolettia tenella (DC.) H. Rob., D–E Pseudopegolettia thodei (Phillips) H. Rob., Skvarla & V.A. Funk, note: images show the leafy stem of P. tenella and the succulent basal leaves of P. thodei; F–G Vernoniastrum latifolium (Steetz in Peters) H. Rob.. See Appendix C for citation details.

Figure 24. 

Scanning electron micrographs of Pseudopegolettia. A–H Scanning electron micrographs of acetolyzed sublophate-echinolophate pollen of Pseudopegolettia tenella (DC.) H. Rob. A Polar view B Equatorial view with prominent lophal ridges surrounding pore C Lateral view D Polar view, slightly different from A E Equatorial view F Lateral view slightly different from C G and H are fractured grains showing the thickened and distally bifurcated support columellae for the overlying exine. From Sidley 3904.

Most notable secondary metabolites include sesquiterpene glaucolides (Bohlmann and Jakupovic 1990 as Vernonia monocephala Harv.) and 5-alkylcoumarins (Bohlmann and Jakupovic 1990 as Vernonia galpinii Klatt).

The genus consists of mostly monocephalous species, but those species have many individual differences such as the restriction of leaves to a basal rosette, capitula structure, and pubescence of the achenes. They do have essentially identical pollen, but it is a widely distributed pollen type in the Erlangeinae. There are no unique or uncommon characteristics that the two species share.

South Africa (Transvaal, Natal).

The older De Candolle name has been placed rather consistently in synonymy, but not adopted. It is only comparatively recently that the combination was occuppied in Vernonia, as Vernonia tenella D.Nash, Fieldiana, Bot. 36: 74. 1974 = Lepidaploa tenella (D.Nash) H. Rob. The epithet tenella still has priority in almost all other genera. The DeCandolle specimen is known in this study primarily from synonymy, description, and on the basis of microfiche (IDC DeCandolle Herbarium 197: III: 8).

Zambia, Transvaal (Smith 1971).

The specimen cited by Smith (1971) as Vernonia nyassae Oliv. from Transvaal, is Pseudopegolettia thodei. The two species have generally similar habits, but they are totally different entities with basically different pollen.

It is evident from the description that Vernonia collina of Klatt, based on a Schlechter collection, is not the same as the V. collina of Schlechter. See under unplaced species.

. Annual or perennial herbs 0.3–1.0 m tall; stems pilose, hairs simple with elongate apical cells with slightly asymmetric bases. Leaves alternate. Inflorescence with 1–many heads. Involucre campanulate; involucral bracts ca. 50 in ca. three series, gradate, persistent; receptacle epaleaceous. Florets ca. 50 in a head; corollas reddish-purple, basal tube narrowly funnelform, throat shorter than lobes or anther thecae, lobes pilosulous distally; anther bases acuminate to acutely tailed; apical appendage glabrous, with thin cell walls. Style base with node; style branches with acicular sweeping hairs. Achenes 4–6-angled, setulae aparse on sides, idioblasts usually grouped in transverse bands, raphids elongate; pappus bristles subpersistent, marginally densely barbellate; outer squamae persistent. Chromosome number n = 10 (Jones 1979, 1982).

Pollen triporate, lophate, perforated tectum discontinuous in lacunae, muri papillate, with or without micropunctations on muri (Fig. 25 D–I).

Figure 25. 

Scanning electron micrographs of Vernonella and Vernoniastrum. A–C Scanning electron micrographs of acetolyzed sublophate-echinolophate pollen of Vernonella africana Sond. A Polar view B Equatorial view C Oblique polar view. A–C from Wood 753. D–I Scanning electron micrographs of acetolyzed echinolophate pollen of Vernoniastrum nestor (S. Moore) H. Rob., showing diversity of lacunae and lophae. D–H Oblique and near polar views showing apertures in markedly long lacunae with irregular lophae H Lateral view with apertures (arrows) occupying long lacunar spaces I Enlarged section of surface showing columellae in irregular rows under muri). D–I from Reekmans 9185.

With habit similar to Polydora but often perennial, lacking L-shaped hairs, having tailed anther bases, and a chromosome number n = 10. Also characteristic of the core element of Vernoniastrum are the transverse bands of crowded idioblasts in the achene walls.

Tanzania, Mozambique, Zimbabwe.

Angola and Congo east to Mozambique and Tanzania, Namibia.

West Africa east to Tanzania, Mozambique, Zimbabwe, Natal.

Species reviewed by Smith (1971) and Robinson and Skvarla (2010a).

Annual or perennial herbs, with leaves rosulate or on leafy stems, basal rosettes often withered at anthesis, bases of plants erect, with or without a dense basal cloak of hairs. Hairs simple or lacking on stems. Inflorescences monocephalic, laxly cymose or densely corymbiform, with short to very elongate peduncles. Heads broadly campanulate; involucres 3–6-seriate, bracts broadly to narrowly oblong, gradate with basal bracts often more lanceolate, tips of inner bracts often obtuse to rounded or apiculate, distally and marginally rather scarious, often purplish. Florets 10–50 or more in a head; corollas purple, with long slender basal tube, throat short, not noticeably broadened at base, lobes linear, usually contorted with age, bearing glands, simple hairs, or L-shaped to T-shaped hairs; anther thecae calcarate and blunt at base, without tails; apical appendage oblong-ovate, with thin cell walls; style base with annulus of thickened, quadrate cells; sweeping hairs slender with sharp, narrow tips. Achenes with ca. 10 ribs, setulose on ribs, setulae with paired cells separated in distal third or less, with numerous idioblasts on surfaces between ribs; raphids in achene wall narrowly elongate. Chromosome number n = 9 (Jones 1982).

Pollen ca. 30–40 μm in diameter when dry, tricolporate with short or truncated colpi, sharply echinate with elongate spines, sublophate with large irregularly shaped lacunae, perforated tectum continuous in lacunae (Fig. 25 A–C).

Notable secondary metabolites include sesquiterpene lactones (elemanolides and eudesmanolides).

The genus Vernonella is most notable for its often solitary heads, simple vegetative hairs, the comparatively limited differentiation of the involucral bracts, unexpanded corolla throats, and the comparatively small sublophate rather than lophate pollen with uniquely truncated colpi. On the basis of the examination of the type species, the detailed studies of Smith (1971), and reviews of literature, eleven species are recognized in the genus. The genus is restricted to Africa and is distributed from Cameroon and Sudan in the north southward to Natal in South Africa.