Curarea toxicofera (Wedd.) Barneby & Krukoff.

Lianas, dioecious, growing in canopies or understory; branchlets villous, strigose or strigillose-tomentellous to glabrate, conspicuously ridged. Leaves simple, spirally arranged; blade narrowly to broadly ovate or elliptic, oblong, broadly elliptic, suborbicular, less frequently obovate; attached to the petiole at the base or scarcely subpeltate, chartaceous to coriaceous, base truncate or obtuse to rounded or slightly cordate, margin entire (or very rarely minutely undulate, weakly lobed or apically bilobed in C. candicans), apex retuse (cleft), acute or acuminate, rarely mucronulate, often cuspidate in young shoots, surfaces usually discolorous, especially when juvenile, lustrous and glabrous adaxially, but midrib sometimes sparsely tomentose, abaxially with finely silvery tomentellous, strigillose-tomentellous or web-like indumentum or the latter coarse and cream or dark brown villous, sometimes restricted to the areolae with age; palmati- to plinerved, (3–)5–7 main veins, the innermost pair perfect or imperfect acrodromous, secondary veins 0–2(–3) pairs or rarely absent, departing from midrib above the middle of the blade; petiole terete, tomentose to glabrate, pulvinate at both ends, apical pulvinus usually more conspicuous, the surface weakly rugulose, sometimes adaxially flattened. Inflorescences are solitary or fascicled, cauliflorous, axillary, supra-axillary or terminal on young shoots, basically thyrsi or simple dichasia; bracts subtending the primary branches lanceolate, narrowly ovate or ovate, markedly concave, fleshy, glabrous adaxially, variously pubescent abaxially, indument appressed or spreading. Staminate inflorescence with the axes sometimes conspicuously ridged; primary branches either lax, with several branching orders or compact and with few branching orders, pauci or multiflowered, variously pubescent. Pistillate inflorescences, with primary branches consisting of simple dichasia or these reduced to single flowers, mostly pauciflorous. Flowers are unisexual, actinomorphic and trimerous; pedicels conspicuous (absent in staminate flowers), terete, moderately slender, sometimes ridged, pubescent; bracteoles 1–2(4), usually early caducous, especially in staminate flowers. Staminate flowers are cream, whitish, greenish, yellowish, orangish, greyish or brownish; sepals 6(–9), in 2(–3) unequal whorls (spirally arranged), free, mostly ovate, narrowly ovate to obovate, oblong, rhombic, elliptic or suborbicular, inner whorl larger than outer one, both whorls weakly concave, scarce fleshy, glabrous adaxially and variously densely pubescent abaxially, tip of inner sepals erect or reflexed past anthesis; petals (5–)6 in 2, more or less similar whorls, smaller than the inner sepals, free narrow or broadly obovate-trilobed, obovate-rhombic or spatulate, weakly concave, membranous, glabrous adaxially, glabrous to densely tomentellous abaxially, base cuneate to distinctly clawed, lateral margins weakly to strongly inflexed and partially clasping the filaments, rarely those of the inner whorl adaxially connate, apex acute, obtuse, truncate or retuse; stamens (3–)6 in (1–)2 similar whorls, filaments free or variously connate, clavate, clavate-sigmoid or weakly terete, glabrous adaxially, glabrous or tomentellous abaxially, anthers basifixed, erect or weakly incurved, the connective is frequently thicker adaxially and forms a keel or a hump at the base or at the apex of the anther, less frequently forming a horn-like structure beyond the anthers; thecae latrorsely opening by longitudinal slits, sometimes anthers splitting into two halves (i.e. abaxial and adaxial) due to the reduction of the connective; pistillode 0. Pistillate flowers are green, yellowish or brownish coloured; sepals 6–9 in 2–3 unequal whorls, free, ovate-lanceolate, elliptic, ovate, broadly ovate, oblong or rhombic, glabrous adaxially, pubescent abaxially, tips of inner sepals usually reflexed after anthesis; petals 3(–6), free, spatulate, weakly concave, membranous, glabrous adaxially, glabrous to sparsely tomentellous abaxially; staminodes 0; carpels 3(–4), tomentose, free, sometimes proximal half coherent when young, style slightly tapering distally, stigma inconspicuous. Infructescences sometimes lenticellate or with the bark exfoliating; fruiting pedicels weakly clavate or terete, at times inconspicuous; carpophores are elongated and terete in understory species or short and subglobose in canopy species (drum-like in C. candicans). Drupelets oblongoid, ellipsoid, broadly obovoid or subglobose, sometimes weakly flattened laterally, sessile or rarely gradually narrowing toward the base, thus rarely forming a short stipe; stylar scar basal and frequently conspicuous; exocarp thin to thick (including the several layers immediately beneath the epidermal layer), coriaceous when dried, smooth, rugulose or muriculate, densely pilosulose, velutinous to glabrate, dull orange to yellow when ripe; mesocarp mucilaginous; endocarp thin and papyraceous or crustaceous, surface smooth or weakly ribbed along its long axis, less frequently there are also transversal ribs. Seed with endosperm absent, embryo hippocrepiform, cotyledons thick, accumbent, sometimes unequal.

The species is distinguished by its coriaceous leaves that are narrowly ovate or elliptic, with dense brown villous indumentum, primary branches of the staminate inflorescence contracted/condensed and drupelets broadly obovoid or ellipsoid.

Ecuador. Pastaza: Pastaza Canton, pozo petrolero “Moretecocha” de ARCO 75 km al. este de Puyo, bosque húmedo tropical, 01°34'S; 77°25'W, 580 m, 4–21 Oct 1990, (♂ fl), Gudiño, Quelal & Caiga 952 (holotype: MO!; isotypes: QCNE!, NY!, US!).

Ortiz-Gentry (2000; unpublished MS thesis) provisionally used the epithet phaeofusca for this taxon.

Large canopy lianas about 20–30 m tall; older stem 6–20 cm wide, strongly flattened, with shallow lengthwise fissures; bark dark brown; branchlets densely coarsely dark brown villous tomentose. Leaves: blades 9–15 × 6–11 cm, ovate to elliptic, subcoriaceous to coriaceous when mature or when exposed to direct sunlight in the canopy; surfaces discolorous, lustrous and glabrous adaxially, coarsely dark brown or cream villous abaxially, trichomes concealing the epidermis at all stages, base obtuse to rounded, apex acuminate or retuse, cuspidate when juvenile, 5(7) palmati- or plinerved, innermost pair of main veins acrodromous perfect on mature leaves, acrodromous imperfect on juvenile ones, midrib and secondary veins slightly impressed adaxially, conspicuously raised abaxially, secondary veins 1–2 pairs, arising above the middle of the blade, veinlets immersed on the adaxial surface, raised abaxially; petioles 2.5–8.5(–15) cm long, terete, densely dark brown villous, apical pulvinus terete, rugulose. Staminate inflorescences solitary, axillary or slightly supra-axillary, thyrsi (Fig. 11A–B), densely dark brown villous; axes 7.4–9 cm long; primary branches, 1.2–1.9 cm long, with compact and reduced (0–1) branching orders; bracts 0.9–1.1 mm long, narrowly ovate, concave, fleshy, glabrous adaxially, dense dark brown villous abaxially. Pistillate inflorescences, solitary or fascicled, axillary, few-flowered thyrsi, the primary branches reduced to single flowers (Fig. 12A), indumentum as on staminate inflorescences; axes 4.8–5.3 cm long, terete or angular; bracts 0.7–1.1 mm long, ovate, concave, fleshy, glabrous adaxially, brown villous abaxially. Staminate flowers 1.4–1.7 mm long, cream to brownish; pedicels ca. 0.9–1.9 mm long, terete, indumentum as on the axis; bracteoles 1–2, 0.3 × 0.1–0.2 mm, ovate to oblong, fleshy, glabrous adaxially, brown tomentose abaxially; sepals 6, glabrous adaxially, brown tomentose abaxially; outer sepals 0.6–0.7 × 0.3–0.5 mm, ovate or oblong, base truncate, apex acute; inner sepals 1.3–1.5 × 1–1.3 mm, obovate or obovate-rhombic, base obtuse, apex obtuse or rounded, tip of inner sepals erect but not reflexed past anthesis; petals 6, 0.6–0.7 × 0.3–0.5 mm, inner ones a little narrower, obovate-rhombic, weakly concave, glabrous adaxially and abaxially, base obtuse to cuneate-truncate (shortly clawed), lateral margins inflexed, partially clasping the filaments, apex obtuse, acute or weakly retuse; stamens 6; filaments 0.4–0.5 mm long, clavate, moderately thick, free or shortly connivent, glabrous; anthers 0.2–0.3 mm long, erect, connective forming a conical-shaped protrusion adaxially, (Fig. 11G), not protruding beyond thecae apically. Pistillate flowers 1.6 mm long, brownish; pedicels 3.2–3.6 mm long, terete; bracteoles 2, 0.4–0.5 × 0.3 mm, ovate, fleshy, glabrous adaxially, brown tomentose abaxially; sepals 6–9, in 2–3 whorls, weakly concave, slightly fleshy to fleshy, glabrous adaxially, brown tomentose abaxially; outer sepals, 0.6–0.9 × 0.3–0.6 mm, ovate or oblong, base truncate, apex obtuse; middle sepals ca. 0.9 × 0.8 mm, obovate, base and apex obtuse; inner sepals 1.1–1.6 × 1–1.5 mm, weakly obovate or elliptic, base and apex obtuse, tips erect to reflexed past anthesis; petals 3, 0.8–1.3 × 0.6–1.4 mm, spatulate, weakly concave, glabrous adaxially, glabrous or sparsely tomentose abaxially, base clawed, apex retuse; carpels 3, 0.4–0.9 × 0.3–0.7 mm, dark brown villous tomentose, indumentum appressed-ascending; style 0.4–0.5 mm long. Infructescences axes 2–6.7 × 0.3–0.5 cm, indumentum as on pistillate inflorescences; fruiting pedicel 0.3–0.6 cm, clavate; carpophores triangular or subglobose, ca. 3.6 mm long, convex at apex, dark brown villous. Drupelets 2.9–4.5 × 2.3 3.1 cm, yellow or orange when ripe, narrowly obovoid to ellipsoid (Fig. 12F), weakly laterally flattened, at times gradually attenuate toward the base; base obtuse, strongly eccentrically attached; stylar scar not apparent; exocarp 4–6 mm thick, surface rugose, dark brown villous tomentose, granular when dried; mesocarp thin, mucilaginous; endocarp 2.5–3.5 × 1.5–1.9 cm, chartaceous, surface smooth. Seeds with embryo 5.8–6.9 cm long, cotyledons slightly unequal.

Figure 11. 

Curarea barnebyana staminate plant: A flowering branch B detail of inflorescence C flower bud D inner sepal, adaxial surface E–F outer and inner petals, adaxial and abaxial surfaces G–H outer stamens, latero-adaxial and abaxial surfaces (based on Gudiño et al. 952).

Figure 12. 

Curarea barnebyana pistillate plant: A inflorescence B flower C opened flower showing the petals and carpels D innermost sepal, adaxial surface E petal, abaxial surface F fruit, lateral surface. (A–E based on Ortiz & Vargas 200F based on Dik 1213).

Andean foothills of eastern Ecuador and eastern Peru (Fig. 9), at elevations of 200–450 m in tropical wet forest. Staminate flowering specimens were collected in January, June and October; fruiting and old pistillate flowering specimens were collected in January and June.

“jondomebo” (Huaorani) (Gudiño et al. 952, ♂ fl).

The specific epithet honours the late Dr. Rupert C. Barneby whose work has laid the foundations for all subsequent taxonomic studies of neotropical Menispermaceae.

The calculated Extent of Occurrence (EOO) based on ten collections representing six localities of C. barnebyana resulted in 72,674 km², whereas the Area of Occupancy (AOO) was estimated as 24 km². Of the six sub populations representing four locations, two of the latter are found nearby private or national protected areas in eastern Ecuador and is very likely that more individuals will be found within these areas. Of the two other locations found across the border, in Peru, one of them is in a rather continuous tract of forests, whereas the other is found in a nearby area where there is increasing deforestation, which may result not only in a decline in habitat quality, but also likely reduction of the geographic range of the species in the future. Based on these considerations, C. barnebyana is assigned a preliminary status of “Vulnerable ” [VU, A3c + B1b(i,ii,iii,iv) + B2b(i,ii,iii,iv)].

C. barnebyana is recognised by its large obovoid or ellipsoid and weakly laterally flattened drupelets covered with a dark brown villous tomentose indumentum and borne on claviform fruiting pedicels. Similar indumentum is found in C. tecunarum, but the primary branches of the staminate inflorescences of the latter are laxly branched, while the primary branches of the inflorescences of C. barnebyana are condensed similar to those of C. crassa and C. candicans (see discussion under C. crassa). Shared anatomical features amongst these species, which make up group 1, are summarised in Table 5. In the fruiting condition, C. barnebyana loosely resembles C. crassa, but it is readily distinguished by its relatively long (ca. 8 cm in length) infructescence axis, clavate fruiting pedicels and narrowly obovoid to ellipsoid drupelets that are weakly laterally flattened and have a dark brown indumentum. Curarea crassa, on the other hand, has a short (ca. 0.5–2 mm long) infructescence axis, terete fruiting peduncles and broadly obovoid drupelets with a dense, golden villous indumentum.

ECUADOR. Napo: Parque Nacional Yasuní, Pozo Petrolero Daimi 2, 00°55'S; 076°11'W, 200 m, 26 May–8 Jun 1988, (fl bud), Cerón & Hurtado 4094 (MO!, QCNE!); Canton Tena Estación Biológica Jatun Sacha, 8 km al. este de Misahuallí, bosque muy húmedo tropical, 01°04'S; 077°36'W, 400 m, 23–31 Jan 1989, (imm fr), Cerón 6008 (G!, MO!, NY!, QCNE!); Reserva Etnica Huaorani, Carretera y oleoducto de Maxus en construcción, km 86–89, 00°51'S; 76°15'W, 260 m, 25–30 Mar 1994, (mat fr), Dik 1213 (MO!, QCNE n.v.); Canton Tena Estación Biológica Jatun Sacha, 450 m, 7 Jan 1989, (imm fr), Neill 8705 (G!, NY!, QCNE!); ibid., (♀ fl & imm fr), Neill 8712 (G! [2], MO!); Estación Biológica Jatún Sacha, 28 Jun 1996, (♀ fl & imm fr), Ortiz & Vargas 194 (MO! [2]); ibid., 29 Jun 1996, (♀ fl & imm fr), Ortiz & Vargas 195 (MO!); ibid., 3 Jul 1996, (♀ fl & imm fr), Ortiz & Vargas 200 (MO!).

PERU. Loreto: Campamento Forestal, 16 km from the Ecuador border near Río Conventes, overgrown road cut margins, [02°25'S; 076°10'W], 12 Apr 1979, (old fr), Aronson & Rodrigues 859 (MO!). Ucayali: Prov. de Padre Abad, distrito de Padre Abad, carretera al. caserío San Miguel y Mapuya, 12–17 km de Aguaytía, bosque primario con abundante luz solar, 09°05'S; 075°26'W, 350 m, 8 Oct 2004, (♂ fl), Schunke & Graham 16307 (F n.v., MO!).

Large canopy lianas ca. 25 m tall; older stem flattened (width unknown); bark dark brown, with shallow lengthwise fissures; branchlets densely brownish to silvery strigose. Leaves: blades 9–23 × 5–12 cm, elliptic, oblong or narrowly ovate, subcoriaceous to coriaceous when mature and up in the canopy; surfaces conspicuously discolorous when juvenile, lustrous and glabrate to glabrous when mature adaxially, silvery web-like indumentum concealing the abaxial epidermis when juvenile, with few brownish trichomes on main veins, densely tomentellous with age, indumentum usually confined to the areolae, base obtuse, rounded or cuneate, margin entire, (minutely undulate –“crispatulo subdentato”– (de Candolle 1818: 543), apex acuminate (bilobulate), cuspidate when juvenile, usually 3–5(7) palmatinerved, less frequently plinerved, innermost pair of main veins acrodromous perfect on mature leaves, usually acrodromous imperfect on leaves from young shoots, midrib immersed or raised adaxially, raised abaxially, secondary veins 0–3 pairs, usually arising above the middle of the blade, veinlets weakly prominent adaxially in juvenile leaves, immersed on mature ones, always raised abaxially, sparsely silvery-tomentose adaxially when juvenile; petioles 2.5–16 cm long, the smaller sizes are frequently associated with canopy leaves and thus fertile plants, silvery, greyish or rufous strigillose-tomentellous, the trichomes appressed or ascending, glabrate with age, apical pulvinus conspicuous, rugulose, shallowly grooved adaxially. Staminate inflorescences solitary or fascicled, slightly supra-axillary or axillary, narrowly branched thyrsi (Fig. 13A–B), densely silvery to greyish or rufescent strigillose tomentellous, conspicuously ridged; axes (1.2–)6.5–10.6 cm; primary branches 0.6–2.1 cm long, compact and 1–2(–3) branching orders (Fig. 13B); bracts 0.5–0.9 mm long, ovate, concave, fleshy, glabrous adaxially, abaxially indumentum as on inflorescence. Pistillate inflorescences unknown. Staminate flowers 1.2–1.3 mm long, greenish, yellowish or brownish; pedicels 0.9–5.6 mm long, conspicuously ridged, indumentum as on staminate inflorescence; bracteoles 1–3, 0.3–0.5 × 0.2–0.3 mm, ovate, ovate-lanceolate or oblong, fleshy, glabrous adaxially, silvery tomentellous abaxially; sepals 6, usually 2-whorled (spirally arranged (?) and 8 in number, Steyermark et al. 125686), glabrous adaxially, silvery tomentellous abaxially; outer sepals 0.7–1.2 × 0.2–0.6 mm, narrowly ovate or ovate-lanceolate, base obtuse or truncate, apex acute (middle sepals ca.1–1.2 × 0.7 mm, obovate, base obtuse, apex rounded); inner sepals 0.9–1.6 × 0.8–1 mm, obovate to suborbicular, base obtuse, apex acute or obtuse (weakly retuse), tip of inner sepals erect to reflexed past anthesis; petals 6, 0.4–0.8 × 0.2–0.6 mm, inner ones slightly shorter and narrower, obovate to obovate-trilobed, weakly concave, membranous, glabrous adaxially, glabrous to sparsely tomentellous abaxially, base cuneate, lateral margins inflexed, partially clasping the filaments, apex obtuse or truncate; stamens 6, filaments 0.2–0.6, mm long, inner ones slightly longer, clavate-terete, moderately thick, free or connivent, glabrous; anthers 0.1–0.3 mm long, erect, connective slightly protruding apically, thicker adaxially and forming a protruding keel at the base of the anthers or shortly overgrowing thecae when older (Fig. 13G–H). Pistillate flowers unknown. Infructescences axes 2.5–2.7 × 0.3 cm, thyrsi (Fig. 14A–B), velutinous; fruiting pedicel 0.5–1.1 cm long, terete; carpophore drum-like, ca. 1.3 mm long, apically weakly concave, velutinous. Drupelets ca. 2.5 × 1.7 cm, (colour when ripe unknown), broadly ellipsoid to subglobose (Fig. 14B), slightly eccentrically attached, base obtuse; stylar scar weakly protruding; exocarp 2 mm thick, surface rugulose or weakly muriculate, velutinous, granular when dried; mesocarp not seen; endocarp papyraceous, surface smooth. Seeds and embryo not seen.

Figure 13. 

Curarea candicans staminate plant: A flowering branch B detail of inflorescence C flower bud D inner sepal, adaxial surface E–F outer and inner petals G–H outer stamens, latero-adaxial and lateral surfaces (based on Pipoly & Boyan 8982).

Figure 14. 

Curarea candicans pistillate plant: A branch showing fruiting peduncle with no fruits B fruiting branch (based on [Jardim Botanico do Rio RB-19508]).

North-eastern South America, from southern Venezuela, Guyana, Suriname, French Guiana and northern Para in Brazil (Fig. 9), in Terra Firme forest from near sea level to 710 m in Lely Mt., Suriname. Staminate flowering specimens were collected in January, July, October and November; the single fruiting specimen was collected in February.

Guyana: “teteabo (Arawak), “granny’s backbone” (Creole), (Sandwith 1930, Sandwith 561, ♂ fl); used in the preparation of “warrou’s other kind of poison” (Jenman 5199, ♂ fl). Suriname: “dobroedoea” (Vreden 11706, st). Venezuela: “shiña-ten” (Steyermark et al. 125686, ♂ fl bud).

The epithet “candicans” doubtlessly stems from the silvery indumentum on the abaxial surface of leaves, which is dense and matted in young individuals.

Analysis of the seven collections representing seven localities resulted in an Extent of Occurrence (EOO) of 209,650 km² and an Area of Occupancy (AOO) of 28 km². Of the seven subpopulations, the most recent collection –a sterile specimen– was made in 2004. While the species has not been collected during the past decade, which may be suggestive of population decline, it is also likely that, due to its climbing habit, the species might have been overlooked by collectors. Additionally, one of the seven individuals occurred in a nature reserve in Venezuela and the locality where one collection was made in French Guiana in the early 1990s, has also become a nature reserve. Based on these observations and the results of the assessment, C. candicans is assigned a preliminary status of “Least Concern” (LC).

The drum-like carpophores of C. candicans (Fig. 14B) are unique in the genus. In all other species, these are elongated or subglobose. Vegetatively, C. candicans is also distinctive on account of the sparse appressed or ascending brownish trichomes on main veins and dense silvery web-like indumentum on the abaxial surface of leaves from young shoots. This indumentum later changes to a tomentellous cover that usually becomes restricted to the areoles with age. The only other species with similar web-like indumentum is C. gentryana, described below, but this lacks the brownish appressed trichomes on the main veins of C. candicans and, moreover, its web-like indumentum persists on old leaves. When leaves of C. candicans are tomentellous and this indumentum is not yet restricted to the areoles, they are indistinguishable from those of C. toxicofera and C. cuatrecasasii. However, neither of the two occurs in the Guianas and both have laxly branching rather than compact primary branches of the inflorescences of C. candicans.

In a family-wide phylogenetic analysis, C. candicans is recovered as sister to the remaining sampled species and support for this placement is high (Ortiz et al. 2016). It shares similar narrowly branched secondary axes in the staminate inflorescences with C. crassa and C. barnebyana.

The type of Abuta candicans, the basionym of Curarea candicans (Rich. ex DC.) Barneby & Krukoff, is a sterile and unnumbered Richard collection from French Guiana (deposited in the P herbarium). Although the specimen in question shows features usually not associated with the remaining specimens referred to C. candicans, such as leaves with bilobulate apex, minutely undulate margins and penninerved venation, these features have sporadically been observed in a few sterile specimens of other Curarea species, although not in the same combination on the same specimen. I follow earlier workers in accepting this sterile specimen as the type of the basionym of Curarea candicans; as described by de Candolle (1818), the leaves are abaxially “glabris candicantibus”, hence the specific epithet, which highlights a distinctive feature of this species. However, in order to unequivocally fix the application of the name, an epitype is being designated is this study.

On another unnumbered collection of Richard, also at P, one of the four labels has the annotation “Type coll. 2” made by Krukoff in 1968. This specimen is rather dissimilar from the type material: its leaf blades are elliptic, the apices are not bilobed and the secondary veins arise beyond the middle of the leaf, towards the apex; however, the abaxial surface is whitish. A comparison of this second specimen with other collections from the region suggests that it is conspecific with the fertile representatives of the species. However, there is no indication in de Candolle’s original description of the existence of another specimen and he described the lamina as having a bilobed apex; thus this second specimen should not be considered part of the original material.

In the protologue, von Martius (1841) contrasted Cocculus dichroa with Abuta candicans. Eichler (1864) considered the two conspecific and placed Cocculus dichroa as a synonym. Similarly, Miers (1871: 392) in listing Abuta ? candicans as a presumed species, imperfectly known species in current terminology, he also listed Cocculus dichroa as synonym of A. candicans. Miers also noted that, due to its lack of inflorescences, it was uncertain whether the specimen in question belonged in Abuta or in Chondrodendron. Subsequently, Cocculus dichroa Mart., has been considered a synonym of Sciadotenia candicans (Rich. ex DC.) Diels (Diels 1910), Chondrodendron candicans (Rich.) Sandwith (Sandwith 1930) and, more recently, Curarea candicans (Rich. ex DC.) Barneby & Krukoff (Barneby and Krukoff 1971).

The sterile type material of Cocculus dichroa at M, image from JStore, has the leaf blades ovate, with a long-acuminate apex and the adaxial surface somewhat bullate. While ovate and long-acuminate leaves are characteristic of juvenile leaves of all species of Curarea, however a somewhat bullate adaxial surface has not been observed in C. candicans. This vegetative feature might turn out to be a distinguishing character when studied in more specimens and the extent of morphological variation C. candicans is better understood. At this time however, C. candicans is the only other species known to occur in Para and, in this study, I hesitantly follow earlier workers in the family in including C. dichroa as a synonym of C. candicans.

BRAZIL. Pará: Santa Isabel. Ea. de F. [Estrada de Ferro] de Bragança, 15 Feb 1909, (detached old fr), collector unknown, (RB n°. 19508!).

FRENCH GUIANA. Cayenne: Richard s.n., no date, (st), (P!). Saül: Vicinity of Eaux Claires, Sentier Botanique, between Crique Tortue and Split in trail, 03°37'N, 053°12'W, 200-400 m, 1 Nov 1992, (♂ fl), Mori et al. 22743 (NY!).

GUYANA. Demerara: Mabura Hill, Ekuk compartment, mixed forest on loamy sand, 05°10'N; 058°45'W, 12 Oct 1989, (♂ buds & fl) Jansen-Jacobs et al. 1995, (NY!, U!); Upper Demerara-Berbice, Pibiri Research Site, 53 km S of Mabura Hill, 05°01'N; 058°37'W, 2 Feb 2004, (st), Torke et al. 310 (MO!). Cuyuni-Mazaruni Region: Kartabo, Willems Timber Concession, Wallaba (Eperua) forest on white sand, 06°21'N; 58°50'W, 100 m, 22 Jan 1989, (old ♂ fl), Hahn & Tiwari 5136 (US!). Essequibo: Basin of Issororo River, 1888, (♂ fl), Jenman 5199 (K!); Essequibo River, Moraballi Creek, near Bartica, near sea level, 6 Nov 1929, (♂ fl), Sandwith 561 (K! [3], NY n.v.).

SURINAME. Without locality, Nov 1941, (st), Krukoff 12305 (GH!, NY n.v.); Railroad Paramaribo-Dam, Nov 1941, (st), Krukoff 12335 (GH! [2], NY n.v., US n.v.); In hellingbos tussen, km 11.0 en 11.1, montibus, qui dicuntur Nassau, 17 Mar 1949, (st), Lanjou & Lindeman 2775a (NY n.v., U!); ibid., (st), Lanjouw & Lindeman 2779 (NY n.v., U!); Nickerie, area of Kabalebo Dam Project, 30–130 m, Boegroemaka forest on gentle slope towards creek, west of road, km 80, 04°00'N; 57°30'W, 22 Sep 1980, (st), Lindeman et al. 539 (U!); Lely Mts., SW plateaus covered by ferrobauxite, forest on plateau S of camp 4, 550–710 m, 5 Oct 1975, (st), Lindeman et al. 805 (MO!, NY n.v.);

Open spot from fallen tree near 7100 m in line from road, km 80 eastward, area of Kabalebo Dam Project, 30–130 m, 11 Nov 1981, (st), Lindeman & de Roon 808 (U!); Mapane Creek area, along Sarwa road, plot in succession, no date, (st), Vreden 11663 (U!); Mapane Creek area, 29 Apr 1967, (st), Vreden 11706 (U!); Without locality, (st), no date, collector unknown (U-32454-B!).

VENEZUELA. Amazonas: Atabapo, Rio Cunucunuma, entre las comunidades La Culebra y Huachamacari, entre El Cerro Duida y Huachamacari, 03°40'N; 065°45'W, 180-210 m, 28 Jan–8 Feb 1982, (♂ fl bud), Steyermark et al. 125686 (MO!, NY!, US!).

Large canopy lianas ca. 24 m tall; older stems with the lower part strongly flattened (width unknown); bark greyish to dark brown; branchlets dense and coarsely golden to silvery villose. Leaves: blades 8–10 × 6–9 cm, broadly elliptic to suborbicular, (narrowly ovate), coriaceous when mature or when directly exposed to sunlight in the canopy; surfaces discolorous, lustrous and glabrous adaxially, but sometimes sparsely tomentellous on main veins, golden or cream villous abaxially, the indumentum concealing the epidermis at all stages, base truncate to widely obtuse, margin entire, apex acuminate (especially when juvenile or not directly exposed to sunlight) to acute or retuse when mature or exposed to direct sunlight up in the canopy, 5–7 palmati- or plinerved, innermost pair of main veins acrodromous perfect on mature leaves, acrodromous imperfect on juvenile ones, secondary veins 0–2 pairs, arising almost at the apex of the blade, all veins slightly immersed adaxially, raised abaxially, but concealed by the indumentum; petioles 2.7–4.5 cm long, ridged, sparsely to densely golden or silvery villous, apical pulvinus conspicuous, rugulose, slightly flat to shallowly grooved or rounded adaxially. Staminate inflorescences solitary or fascicled, axillary or supra-axillary, thyrsi (Fig. 15A–B), golden villous tomentose; axes 9.8 cm long; primary branches compact and up to 1.1 cm long, with reduced (0–1) branching orders; bracts ca. 0.8 mm long, ovate, concave, fleshy, glabrous adaxially, golden villose abaxially.

Pistillate inflorescences (old) solitary or fascicled, axillary, few-flowered thyrsi, indumentum as on staminate inflorescences; axes ca. 3.8 cm long; bracts not seen, primary branches 0.6 cm long, indumentum as on the axis. Staminate flowers ca. 1.4 mm long, pale cream; pedicels ca. 1.3 mm long, terete, indumentum as on the axis; bracteoles 2, ca. 0.5 × 0.3 mm, narrowly ovate, fleshy, glabrous adaxially, light golden tomentose abaxially; sepals 6, indumentum as on bracteoles; outer sepals ca. 0.8 × 0.5 mm, ovate-lanceolate to ovate, base truncate, apex acute to obtuse; inner sepals ca. 1.4 × 1.3 mm, obovate or rhombic, base and apex obtuse, tip of inner sepals erect to hardly inflexed past anthesis; petals 6, ca. 0.7–0.8 × 0.6 mm, obovate, weakly concave, membranous, glabrous adaxially and abaxially, base cuneate, lateral margins inflexed, partially clasping the filaments, apex truncate or weakly retuse; stamens 6; filaments ca. 0.5 mm long, clavate, thick, free, glabrous adaxially and abaxially; anthers ca. 0.3 mm long, erect, connective thicker adaxially and forming a protruding keel at the base of the anthers (Fig. 15H), not overgrowing the thecae when older. Pistillate flowers ca. 2.1 mm long, greenish; pedicels ca. 0.5 mm long, appearing ridged, indumentum as on staminate inflorescences; bracteoles 2, 0.7 × 0.4 mm, ovate-lanceolate, fleshy, glabrous adaxially, light golden tomentose abaxially; sepals 9, in three whorls, glabrous adaxially, light golden tomentose abaxially; outer sepals ca. 0.9 × 0.5 mm, ovate-lanceolate; middle sepals ca. 1.6 × 0.7 mm, lanceolate to ovate-lanceolate; inner sepals 2.1 × 1.2 mm, elliptic or rhombic, their tips erect or weakly reflexed past anthesis; petals 3, ca. 1.3 × 1 mm, spatulate, weakly concave, membranous, glabrous adaxially, sparsely to densely silvery tomentellous abaxially, base clawed, apex truncate to slightly retuse; carpels 3, 1.1 × 0.7 mm, villous; style 0.4 mm long. Infructescences axes ca. 0.5–1.2 × 0.4–0.6 cm, indumentum moderate greyish-silvery tomentose; fruiting pedicels 5.8–6.1 mm long, terete; carpophores subglobose, ca. 2.4 mm long, convex at apex, golden villous. Drupelets 3.5 × 2.9 cm, (colour when ripe unknown), broadly obovoid (Fig. 16A), centrically or only weakly eccentrically attached, base oblique, stylar scar inconspicuous, surface golden villous; exocarp 6.7 mm thick, outer surface rugose, granular when dried; mesocarp not seen, but likely thin and mucilaginous; endocarp ca. 2.6 × 2.2 cm, papyraceous to chartaceous, surface smooth. Seeds and embryo not seen, (horny, ca. 23 × 18 mm, Barneby 1996).

Figure 15. 

Curarea crassa staminate plant: A flowering branch B detail of inflorescence C flower bud D inner sepal, adaxial surface E–F outer and inner petals, abaxial views G–H outer stamens, abaxial-lateral surfaces (based on Thomas et al. 10900).

Figure 16. 

Curarea crassa pistillate plant: A fruiting branch B innermost sepal, adaxial surface C petal, abaxial surface D carpels (based on Jardim et al. 609).

Curarea crassa is known only from the coastal Atlantic Forest of Bahia in Brazil (Fig. 9), at ca. 76 m in elevation. Staminate flowering specimens were collected in May, whereas a pistillate flowering specimen was collected in February and immature fruiting specimens were collected in July and December.

Brazil: “buta” (Fróes 12701/67, st).

Not explained in protologue, but likely the name is in reference to its thick exocarp (mesocarp in original description).

The five collections representing three localities resulted in an estimated EOO of 45 km² and an AOO of 12 km². The three localities correspond to two subpopulations and two locations, of which one is found within a protected area.

However, ongoing deforestation in the largely degraded Brazilian Atlantic forest may negatively affect the already localised subpopulations of C. crassa, further reducing suitable habitat. Based on these considerations, C. crassa is here assigned a preliminary status of “Endangered” [EN B1ab(i,ii,ii,iv,v) + B2ab(i,ii,ii,iv,v)].

Curarea crassa is vegetatively conspicuous because of its broadly elliptic or suborbicular leaves covered with a dense golden or creamy villous indumentum on the abaxial leaf blade surface. Similar indumentum may sometimes also be observed on the abaxial leaf blade surfaces of C. barnebyana and C. tecunarum; from C. barnebyana, it differs by its woolly, greyish-golden indumentum in the staminate inflorescences (vs. dark-brown). From C. tecunarum, C. crassa differs by its primary branches with few branching orders in the staminate inflorescence (vs. primary branches with several branching orders in C. tecunarum). Also, the large and broadly obovoid drupelets are unique to C. crassa.

The thick layer, from which the specific epithet is likely derived, was described as the mesocarp (Barneby 1996), however it is likely that the mesocarp in C. crassa, as in C. barnebyana, C. tecunarum and C. aff. iquitana, is mucilaginous and no longer noticeable in dried fruits, as was the case reported for C. tecunarum (Barneby and Krukoff 1971).

On morphological grounds, C. crassa is placed with the species of Group I. Micro-morphological characters shared amongst species in Group I are summarised in Table 5. Curarea crassa shares its staminate inflorescences with condensed branch orders with species of that group. They differ in the inflorescence indumentum colour, this being cream or golden in C. crassa vs. dark brown or greyish in C. barnebyana. The primary branches of the staminate inflorescences are also condensed in C. candicans, but there, trichomes are strigillose-tomentellous and not villous as in C. crassa.

In the protologue of C. crassa, Barneby (1996) described staminate flowers as having 9 sepals, but only 6 sepals were found in the only staminate plant available in this study (Thomas et al. 10900). This discrepancy is likely due to infraspecific variation as was also occasionally observed in C. candicans and in C. aff. iquitana.

BRAZIL. Bahia: Uruçuca, Serra Grande, 7.3 km na Estrada Serra Grande/Itacaré, Fazenda Lagoa do Conjunto Fazenda Santa Cruz, 14°25'S; 39°01'W [39°03'W], 19 Jul 1994, (♂ fl), Carvalho et al. 4563 (CEPEC n.v., NY! [image seen]; Região da Mata Atlântica, 14 Jul 1995, (imm fr), Carvalho et al. 6031 (NY!); Una, Reserva Biológica do Mico-Leão (IBAMA), entrada no km 46 da rod, BA-001, Ilhéus/Una, Região da Mata Higrófila Sul Bahiana, 8–10 km na Estrada que margeia ao Rio Maruim, 15°09'S; 39°05W, 6 Jun 1996, (imm fr), Carvalho et al. 6222 (CEPEC n.v., NY! [image seen]); Ilhéus, basin of Rio Santa Ana, high forest, near Bom Gosto, 8 Dec 1942 (st), Fróes 12701/67 (A!, NY n.v.); Uruçuca, Serra Grande, 7 .3 km na estrada Serra Grande/Itacaré, Fazenda Lagoa do Conjunto Fazenda Santa Cruz, 14°25'S; 39°01'W [39°03'W], 9 Feb 1995, (♀ fl), Jardim et al. 609 (NY!); 7.4 km north of Serra Grande on road to Itacaré, 14°25'24"S; 039°03'38"W, 12 May 1995, (♂ fl), Thomas et al. 10900 (MO!, NY!).

Medium-sized understory lianas about 5–10 m tall; older stem more or less terete to weakly irregularly flattened, 0.5–1.5 cm wide; bark dark brown, with shallow lengthwise fissures and conspicuously tuberculate-lenticellate; branchlets densely brownish to silvery strigillose-tomentellous to glabrate. Leaves: blades 9–26 × 4.3–13.5 cm, ovate to elliptic, chartaceous at all stages, base obtuse to rounded, apex acuminate, cuspidate when juvenile; surfaces discolorous, lustrous and glabrous adaxially, indumentum finely silvery strigillose-tomentellous abaxially, rarely confined to the areoles with age; 3(5) palmati- or plinerved, innermost pair of main veins acrodromous imperfect at all stages, midrib and lateral nerves slightly raised above, conspicuously raised abaxially, secondary veins 2(3) pairs, veinlets slightly prominent adaxially in both juvenile and mature leaves, raised abaxially; petioles (2.9–)6.2–18 cm long, ridged, rugulose, brownish or silvey strigillose-tomentellous to glabrate, distal pulvinus rugulose. Staminate inflorescences fascicled, cauliflorous, lax thyrsi (Fig. 17B–C), densely silvery or brownish strigillose-tomentellous; axes 2.2–8 cm long; primary branches 1.8–6.2 cm long, filiform, with several (2–)4–5 branching orders; bracts 0.4–1.1 mm long, lanceolate to narrow ovate, concave, fleshy, indumentum as on inflorescence.

Pistillate inflorescences unknown. Staminate flowers 1.2–1.6 mm long, green, greenish or brownish; pedicels 0.4–2.8 mm long, terete, sometimes ridged, indumentum as on the axis; bracteoles 2–3, 0.2–0.6 × 0.1–0.4 mm, ovate-lanceolate, oblong or ovate-rhombic, fleshy, glabrous adaxially, light brown tomentellous abaxially; sepals 6, glabrous adaxially, light brown to silvery tomentellous abaxially; outer sepals 0.8–1 × 0.5–0.8 mm, ovate-lanceolate, ovate or obovate, base and apex obtuse; inner sepals 1.2–1.7 × 0.6–1.1 mm, obovate or elliptic, sometimes oblong or ovate-rhombic, base cuneate, apex acute to obtuse, tip of inner sepals erect to strongly reflexed past anthesis; petals (5)6, 0.5–0.9 × 0.2–0.5 mm, inner ones slightly longer, narrowly obovate-trilobed or spatulate, weakly concave, membranous, glabrous adaxially, glabrous to sparsely silvery tomentellous abaxially, weakly to strongly recurved above the cuneate base, lateral margins inflexed, partially clasping the filaments, apex acute, sometimes obtuse; stamens (3–)6; filaments 0.3–0.7 mm long, inner ones slightly longer clavate to clavate-sigmoid, moderately thick, free or connate at base, glabrous; anthers 0.2–0.3 mm long, erect, connective thicker adaxially and forming (or not) a protruding keel at the base of the anther, sometimes apically overgrowing thecae and forming a hump adaxially when older (Fig. 17H–I). Pistillate flowers unknown. Infructescences axes 1.3–4 × 0.2–0.7 cm, bark exfoliating, cauliflorous, lax thyrsi, with simple dichasia as primary branches, brownish strigillose-tomentellous; fruiting pedicels (1.2–)6.5 mm long, terete to weakly clavate; carpophores 2.4–4.5 mm long, elongate, weakly terete to claviform, truncate or convex at apex, velutinous. Drupelets 1.9–3.2 × 1.2–1.8 cm, yellow or pale orange when ripe, oblongoid or ellipsoid (Fig. 18B), (weakly reniform), weakly to strongly eccentrically attached, base truncate, obtuse to cuneate (gradually narrowed toward the base in a short (3–3.5 mm) stipe; stylar scar conspicuous; exocarp 1.2–1.9 mm thick, surface rugulose or muriculate, velutinous, granular when dried; mesocarp thin, mucilaginous; endocarp 1.5–2.4 × 0.9–1 cm, chartaceous, surface smooth. Seeds with embryo 3.8–4.8 cm long, crustaceous, cotyledons sometimes unequal.

Figure 17. 

Curarea cuatrecasasii staminate plant: A habit B inflorescence C inflorescence detail D flower bud E inner sepal, adaxial surface F–G outer and inner petals, abaxial and lateral surfaces H–I outer stamens, adaxial and abaxial surfaces (based on Aguilar 3303).

Figure 18. 

Curarea cuatrecasasii pistillate plant: A habit B infructescence (A, based on Cuatrecasas & Willard 26168; B based on Marin 246).

From Costa Rica throughout Panama to northwestern Colombia (Fig. 9), at elevations of 10–650(–1100) m. In wet tropical lowland to pre-montane forests. Staminate flowering specimens were collected in March, April, May, June and September; pistillate flowering specimens are unknown; fruiting specimens were collected in January, March and July–December.

Costa Rica: edible fruits (Morales et al. 3243, mat fr). Colombia: used as magic plant by the Waunana (Forero 666, st).

As per Barneby and Krukoff (1971), “the specific epithet honors Dr. José Cuatrecasas, who contributed greatly to the knowledge of the Colombian Flora and was a co-collector of the holotype”.

The calculated Extent of Occurrence (EOO) based on 26 collections representing 25 localities is 184,445 km², whereas the Area of Occupancy (AOO) is estimated as 100 km². Of the 23 subpopulations, 12 occurred in protected areas in Panama and Costa Rica and, although the species is not abundant where it occurs, it has a broad distribution. Hence, C. cuatrecasasii is assigned a preliminary category of “Least Concern” (LC).

Curarea cuatrecasasii is distinguished from its congeners by the combination of slender staminate inflorescences bearing filiform primary branches, petals weakly to strongly recurved shortly above the base, connectives forming an adaxial hump at the apex of thecae when older and ovate or ovate-elliptic, 3–5-veined leaves with silvery strigillose-tomentellous indumentum on the abaxial surface. The staminate inflorescence of this species resembles those of C. gentryana and is discussed under the latter species.

In fruit, C. cuatrecasasii is indistinguishable from C. iquitana, C. tomentocarpa and C. toxicofera and they all share elongate carpophores, but they can be separated geographically: C. cuatrecasasii is restricted to the Pacific side of the Andes from North Eastern Colombia to Costa Rica and the other species are known only from the eastern side of the Andes in Colombia, Ecuador, Peru, Brazil and Bolivia.

The vessels width of C. cuatrecasasii is like that of C. tecunarum and C. barnebyana in being, on average, larger than the remaining species in group II (Table 5).

COSTA RICA. Puntarenas: Reserva Forestal Golfo Dulce, Aguabuena, Sector Norte, [08°42'20’’N; 083°28'30’’W], 50–150 m, 21 Nov 1991, (imm fr), Aguilar 682 (MO!); Parque Nacional Corcovado, Sirena, Corcovado basin trail, [08°29'N; 083°35'W], 50 m, 30 May 1989 (♂ fl), Kernan & Phillips 1147 (CR!, F [2]!, INB!, MO!). San José: Puriscal, Z.P. La Cangreja, faja Costeña del Valle de Parrita, Mastatal de Puriscal, bosque primario en la cuenca del Río Negro, por La Ceiba, 09°41'24"N; 084°23'24"W, 300 m, 25 Nov 1994, (mat fr), Morales et al. 3243 (CR!, MO!).

PANAMA. Canal Zone: Along Rio Mendoza and small tributary, 1/2-1 km upstream from Pipeline Road bridge, 8 km NW of Gamboa, Premontane wet forest, 100 m, 1 Nov 1973, (imm fr), Nee 7731 (COL!, F n.v., MO-2035834, US!. Coclé: Along Llano Grande to Coclesito road above Cascajal, near divide, forest, 08°42'N; 080°28'W, 500 m, 11 Jan 1986, (imm fr), McPherson 7956 (MO!). Colón: Rio Guanche, ca. 2.5 km upriver from bridge on road to Portobelo, [09°30'N; 079°39'W], 10–100 m, 14 Dec 1974, (imm fr), Mori & Kallunki 3695 (MO!). Darien: Area from below the Rancho Frio to near ridgetop of Pirre Chain, [07°49'N; 077°43'W], 600–1100 m, 15 Nov 1977, (imm fr), Folsom et al. 6357 (MO!, NY!). Panama: Pipeline road, premontane wet forest, [09°14'42N; 079°48'53"W–09°07'26"N; 079°42'33"W], 50–120 m, 11 Mar 1983, (♂ fl), Gentry & Hamilton 41126 (MO!); Primary forest, along road between El Llano and Carti-Tupile road, from 12 miles above Pan American Hwy to continental Divide, [09°18'N; 078°56'W–09°19'N; 078°57'W], 200–500 m, 30 Mar 1973, (imm fr), Liesner 1325 (MO-2035837); Pipeline Road, ca. 12 km NW of Gamboa, Tropical wet forest, [09°10'N; 079°45'W], 100 m, 26 Aug 1975, (imm fr), Mori 7946 (MO!). San Blas: Quebrada E of town of Puerto Obaldia, upriver from the dam (represa), [08°40'N; 077°24'W], 0–50 m, 18 Apr 1982, (♂ fl), Knapp & Mallet 4706 (MO!).

COLOMBIA. Antioquia: Mpio. Taraza, corregimiento “El Doce”, Hacienda Las Mercedes, La Quebradona, 200 m NE de Medellin, 650 m, 3 Jul 1980, (imm fr), Callejas 1183 (NY!); Mpio. Chigorodó, vereda Bohios, Finca La Cabaña, 30 m, 4 Apr 1985, (♂ fl.), Renteria 3754 (JAUM n.v., MO!). Bolivar: Mpio. Achi, Inspección de La Raya, 100 m, 6 May 1987, (♂ fl), Cuadros & Gentry 3606, (JBGP n.v., MO!, NY!). Chocó: Mpio. de Riosucio, Zona de Urabá, Cerros del Cuchillo, Sector Cuchillo Negro, 10–30 m, 7 Sep 1987, (imm fr), Cárdenas 374, (JAUM n.v., MO!); Mpio. Bahia Solano, Corregimiento El Valle, trocha El Valle-Boro Boro, 06°21'N; 076°26'W, 17 Apr 1989, (♂ fl), Espina et al. 2645 (MO!).

The species is distinguished from its congeners by its staminate flowers with the lateral margins of inner petals adaxially connate or connivent, also by its large broadly obovoid or ellipsoid drupelet that has a silvery tomentellous indumentum.

Ecuador. Esmeraldas: San Lorenzo Canton, Reserva Indígena Awá, Parroquia Ricaurte, Comunidad Balsareño, Río Palabí, bosque muy húmedo tropical, bosque primario, disturbado, 01°09'N; 078°31'W, 100 m, 15–29 Apr 1991, (♂ fl), Rubio & Quelal 1503 (holotype: MO!; isotypes: NY!, QCNE!).

The earlier listing of the name in Ortiz-Gentry (2000) does not constitute effective publication as per article 30.8 of the Melbourne Code (MacNeill et al. 2012), and is therefore here being validated.

Medium-sized understory lianas ca. 8 m tall, older stems more or less terete, 0.5–1 cm diameter, bark dark brown, with shallow lengthwise fissures and conspicuously tuberculate-lenticellate; branchlets brownish strigillose-tomentellous to glabrate. Leaves: blades 17–22 × 14–23 cm; broadly ovate, base truncate or weakly cordate, apex acuminate, cuspidate when juvenile; chartaceous when mature or when exposed to direct sunlight, otherwise membranous; surfaces discolorous, lustrous and glabrous adaxially, finely silvery web-like abaxially, indumentum concealing the surface, persistent at all stages; 5-palmatinerved, innermost pair of main veins acrodromous imperfect at all stages, midrib and lateral nerves slightly raised to weakly sunken adaxially, conspicuously raised abaxially, secondary veins 2(3) pairs, arising above the middle of the blade, veinlets raised on both surfaces; petioles 11.3–16.9 cm long, ridged, silvery or brownish strigillose-tomentellous to glabrate, weakly pulvinate at both ends, apical one conspicuous, rugulose. Staminate inflorescences fascicled, axillary or cauliflorous, lax thyrsi (Fig. 19A–B), silvery or brownish strigillose-tomentellous to glabrate; axes ca. 7.6 cm long; primary branches ca. 4 cm long, with several (2–5) orders of cymose branching, less frequently the higher branch orders are reduced on alternating sides, appearing racemiform; bracts ca. 1.1 mm long, lanceolate, concave, fleshy, indumentum as on inflorescence. Pistillate inflorescences unknown. Staminate flowers ca. 1.3 mm long, cream; pedicels ca. 0.7 mm long, terete, indumentum as on inflorescence; bracteoles 1–2, ca. 0.2 × 0.2 mm, ovate or oblong, fleshy, glabrous adaxially, silvery tomentellous abaxially; sepals 6, glabrous adaxially, silvery tomentellous abaxially; outer sepals ca. 1 × 0.6 mm, narrowly ovate or ovate-rhombic, base obtuse to truncate, apex acute or obtuse; inner sepals ca. 1.6 × 0.9 mm, obovate or weakly rhombic, base obtuse to cuneate, apex acute to obtuse, tip of inner sepals erect to strongly reflexed at anthesis; petals 6, ca.0.8– 0.9 × 0.4–0.5 mm, narrowly obovate-trilobed to strongly spatulate, the latter the more so when there are only three stamens, moderately concave, membranous, glabrous adaxially, glabrous or sparsely silvery tomentellous abaxially, base cuneate or strongly clawed, lateral margins strongly inflexed, partially clasping the filaments and sometimes the inner ones are adaxially connate or coherent, when 3 stamens are present, apex rounded to slightly retuse or truncate; stamens 3(–6), 1(2)-whorled, filaments ca. 0.6 mm long, clavate, free (or variously connate when 4–6), glabrous; anthers ca. 0.3 mm long, erect, connective adaxially thicker, sometimes forming a keel at the base of the anthers, apically overgrowing thecae and forming a hump when older (Fig. 19H). Pistillate flowers unknown. Infructescences axes ca. (1.3)3.5 × 0.3–0.4 cm, conspicuously lenticellate, strigillose-tomentellous or glabrate; fruiting pedicels (in immature fruits) 4.7–6.3 mm long, terete; carpophores 2.5–3.1 mm long, terete in immature fruits, not seen in mature fruits, truncate at apex, velutinous. Drupelets 3.6–4.6 × 2.1–2.8 cm, (colour when ripe unknown), weakly obovoid or ellipsoid (Fig. 19I), weakly eccentrically attached, base obtuse, stylar scar not apparent; exocarp ca. 2.6 mm thick, surface rugose, sparsely brownish velutinous tomentellous or glabrate, granular when dried; mesocarp thin and mucilaginous; endocarp ca. 3.7 × 2.2 cm, papyraceous, surface smooth. Seeds with embryo ca. 8 cm long, cotyledons unequal.

Figure 19. 

Curarea gentryana staminate plant: A flowering branch B detail of inflorescence C flower bud D inner sepal, adaxial surface E–F outer and inner petals, abaxial and latero-adaxial surfaces G–H outer stamens, abaxial and lateral views I pistillate plant, infructescence (A–H based on Rubio & Quelal 1503I based on Aulestia et al. 9).

Curarea gentryana is known only from northwestern Ecuador (Fig. 9), at elevations of 80–225 m. It is found along creek margins in lowland tropical wet forest. Flowering specimens were collected in April and fruiting specimens were found in February, April and July.

“granadilla” (Rubio & Quelal 1434, imm fr).

The specific epithet honours the late Dr. Alwyn H. Gentry, a dedicated and extraordinary botanist and inspiring mentor, who died tragically in a plane crash in August 1993 while surveying a dry forest reserve in western Ecuador.

The species is known only from four collections from three localities from northwestern Ecuador. Assessment based on these collections resulted in an Extent of Occurrence (EOO) of 92.6 km² and an Area of Occupancy (AOO) of 12 km². The three localities represent three subpopulations, each found in a small communal protected area (Reserva Etnica Awá), the surrounding area of which has been subject to increased land conversion. Therefore, it is expected that the species will in the future be negatively affected by loss of its habitat quality that may lead to reduction in the population and potentially threatening its survival. Thus, C. gentryana is assigned a preliminary status of Endangered [EN, B1ab(i,ii,iii,iv,v) + B2ab(ii,iii,iv,v)].

The velutinous tomentellous indumentum covering the large obovoid or ellipsoid drupelets and the web-like indumentum on the abaxial surface of the broadly ovate leaves are unique to Curarea gentryana. The staminate inflorescences of C. gentryana somewhat resemble those of C. cuatrecasasii. However, C. gentryana has the spatulate inner petals with the lateral margins adaxially connate; spatulate inner petals may also be found in C. cuatrecasasii, but the lateral margins are not adaxially connate.

ECUADOR. Esmeraldas: San Lorenzo Canton, Reserva Indígena Awá, Parroquia Ricaurte, Centro Guadualito, 01°15'N; 078°40W, 80 m, 20–29 Apr 1992, (fr), Aulestia et al. 9 (MO!, QCNE!); Creek on left side of Rio Palaví, going up river, 2 bends up from Awá encampment past first island, 01°07N; 078°37'W, 225 m, 14 Feb 1988, (imm fr), Hoover et al. 4530 (MO!); Comunidad Balsareño, Río Palabí, 01°09'N; 078°31W, 100 m, 15–29 Apr 1991, (fr), Rubio & Quelal 1434 (MO!, QCNE!).

Medium-sized understory lianas, (0.5–)2–7 m tall; older stems more or less terete, up to 1.5 cm diameter, bark dark brown, with shallow lengthwise fissures and scarcely tuberculate-lenticellate; branchlets glabrescent. Leaves: blades (11–)14–37 × (5–)14 –30 cm; ovate to broadly ovate; chartaceous when mature or when exposed to direct sunlight, base obtuse, truncate or weakly cordate, apex acute, acuminate, to cuspidate; surfaces discolorous, lustrous and glabrous adaxially, finely silvery tomentellous abaxially, indumentum concealing the surface at all stages, 3–5 palmati- to shortly plinerved, innermost pair of main veins acrodromous imperfect at all stages, midrib and lateral nerves slightly raised to weakly sunken adaxially, conspicuously raised abaxially, secondary veins 3(4) pairs, arising above the middle of the blade, veinlets raised above and below; petioles (3.9–)12–29.2 cm long, ridged, brownish-greyish strigillose to glabrate, apical pulvinus conspicuous, rugulose, scarcely flattened adaxially. Staminate inflorescences solitary or fascicled, axillary or cauliflorous, thyrsi, brownish to silvery strigillose, indumentum adpressed; axes (2.2–)7–14 cm long; primary branches 1–6 cm long, with (1)4–5 orders of branching; bracts (0.2–)0.7–1.2 mm long, ovate, concave, ascending, fleshy, glabrous adaxially, brown villous tomentellous abaxially. Pistillate inflorescences basically a thyrse, sometimes the primary branches reduced to single flowers, hence appearing racemose, brownish to silvery strigillose; axes 0.6–3.8 cm long; bracts 0.6–1 mm long, ovate, rather fleshy, glabrous adaxially, brownish villous abaxially. Staminate flowers 1.3–1.8 mm long, whitish, greenish, green-yellowish or orangish; pedicels (0.6–)1.3–3.1 mm long, terete, relatively thick, indumentum as on the axis, but somewhat spreading; bracteoles 2–3, 0.23–0.4 mm long, ovate or oblong, fleshy, glabrous adaxially greyish or silver villous-tomentellous abaxially; sepals 6, indumentum as on bracteoles; outer sepals 0.6–1.3 × 0.4–0.7 mm, ovate or ovate-elliptic, base truncate, apex acute; inner sepals 1.2–2.2 × 1–1.5 mm, narrowly ovate, ovate, elliptic or weakly obovate, base obtuse or cuneate, apex acute to rounded, tip of inner sepals erect, sometimes reflexed past anthesis; petals 6, 0.6–1.2 × 0.3–0.8 mm, inner ones slightly smaller and narrower, obovate, obovate-trilobed or flabelliform, weakly to moderately concave, membranous, glabrous adaxially, sparsely silvery tomentellous abaxially, base cuneate or slightly clawed, lateral margins inflexed, partially clasping the filaments, apex acute, sometimes obtuse in the inner ones; stamens 6, filaments 0.4–0.8 mm long, inner ones slightly longer, clavate, free or connivent, less frequently connate ca. half their length, glabrous; anthers 0.2–0.3 mm long, erect, connective protruding adaxially and forming a hump or a horn apically or not, protrusion more conspicuous when older. Pistillate flowers (mostly old) 1.7–2.2 mm long, greenish; pedicels 1.3–5.1 mm long, terete, indumentum as on the axis; bracteoles 1–3(4), 0.2–0.6 × 0.3–0.6 mm, ovate or oblong, rather fleshy, glabrous adaxially, greyish or silvery villous tomentellous abaxially; sepals 6–9(12), weakly concave, moderately fleshy, in 2–3 whorls, glabrous adaxially, greyish or silvery villous tomentellous abaxially; outer sepals ca. 0.5–1.3 × 0.4–0.8 mm, ovate, base truncate, apex acute; middle sepals 0.6–2.2 × 0.6–1.4 mm, broadly ovate to obovate, base obtuse or cuneate, apex acute; inner sepals 1.6–2.2 × 1.3–1.7 mm, ovate, obovate or elliptic, base cuneate or clawed, apex obtuse or rounded, tips erect to weakly reflexed past anthesis; petals 3(4), 1.3–1.7 × 0.6–0.8 mm, spatulate or obovate-trilobed, weakly concave, membranous, glabrous adaxially, glabrous or sparsely silvery tomentellous abaxially, base clawed, apex obtuse; carpels 3, 0.6–0.9 × 0.4–0.6 mm, dark to light brown villose, trichomes appressed-ascending; style 0.6–1.1 mm long. Infructescences axes 1–6 × 0.3–0.9 cm long, at times moderately stout, brown to silvery-strigillose-tomentose or glabrous; fruiting pedicels 2.3–4.6 mm long, terete, sometimes rather thick; carpophores 4–8 mm long, clavate in mature fruits, truncate at apex, cream or brownish velutinous. Drupelets 1.8–2.8 × 1.2–1.6 cm, yellow when ripe, ellipsoid or weakly oblongoid, weakly eccentrically attached, base obtuse, stylar scar basal; exocarp 0.9–1.2 mm thick, surface rugulose, cream or silvery velutinous or glabrescent, granular when dried; mesocarp said to be “clear and slimy” (Berlin 542); endocarp 1.7–2.4 × 0.8–1.2 cm, chartaceous, surface reticulate by scarcely pronounced veins. Seeds with embryo 3.6–4.9 cm long, cotyledons unequal.

Known from the lowlands to mid elevations in eastern to central Peru (Fig. 21), including the departments of Amazonas, Loreto and Pasco, from elevations of 106 m in Loreto up to 1380 m in Pasco. Staminate plants were collected in January-February, July-August and November. Pistillate flowers were found in February, October and December, whereas fruiting specimens were found all year round.

Figure 20. 

Curarea iquitana (photograph of the type of Chondrodendron iquitanum, Tessmann 4196, B).

Figure 21. 

Geographic distribution of Curarea iquitana and C. tecunarum, for the latter selected specimens only, because most of the specimens are sterile.

Peru: “dabau” (Ancuash 660, ♂ fl, Kayap 749, imm fr, 1205, mat fr); “dúpam” (Berlin 542, mat fr); “tsegásnum” (Aguaruna) (Castro et al. 18929, imm fr; Lewis et al. 18475, imm fr); “namaú” (Kayap 156, mat fr); “tseas daek” (Kayap 1032, imm fr); “tsegas” (Kujikat 107, imm fr); “tseusnum” (Ancuash 1219, ♂ fl); “ampihuasca amarilla” (Schunke Vigo 2981, mat fr); “ampihuasca delgadito” (Schunke Vigo 6836, ♂ fl); “ampihuasca negra” (Schunke Vigo 7125, ♂ fl).

Krukoff and Moldenke (1938) cited Chondrodendron iquitanum (Curarea iquitana in this study) as a “source of poison for darts of Indians” based on the label of the sterile Mexia 6321a. This specimen was later identified as Curarea toxicofera (Barneby and Krukoff 1971). I have not examined the referred specimen and hence I have not been able to confirm its identity.

Presumably in reference to Iquitos, the largest city in Peruvian Amazonia and in which general area the type specimen was surely collected.

The assessment was based on 37 collections corresponding to 18 localities that yielded an Extent of Occurrence (EOO) of 279,551 km² and an Area of Occupancy (AOO) of 72 km². The 18 localities represent 17 subpopulations of which four occur within protected areas (Allpahuayo-Mishana National Reserve in the Iquitos area) and three are found on private lands. Although Curarea iquitana is not abundant where it occurs, it is however broadly distributed and hence it is assigned a preliminary status of “Least Concern” (LC).

Curarea iquitana is here resurrected from synonymy under C. toxicofera. Curarea iquitana, as defined here, encompasses a broad range of morphological variation and includes, at least provisionally, what is labelled the allpahuayo group (al.) in the linear discriminant analysis. While the iquitana (iq) and allpahuayo (al.) groups may represent different entities, at present it is premature to recognise them as different species, given that the morphological quantitative characters evaluated in this study partially or completely overlap between the two groups (Fig. 10B).

Additionally, features of pistillate flowers are still fragmentary or lacking, hence the extent of variation, if any, in these features, remains unknown. Collections from the foothills of central-eastern Peru in the Amazonas department from 200–800 m elevation closely resemble the type of Chondrodendron iquitanum Diels (Tessmann 4196), which was collected in the same general area – in the basin of the Marañon River, at 160 m in elevation – around which my concept of Curarea iquitana is centred. These collections tend to have conspicuously large, ovate or broadly ovate leaves with 5–7 main veins. The staminate inflorescences have a brownish to silvery strigillose indumentum and small flowers that range from 1.6 to 1.8 mm long, (mostly greyish villous and 1.3–1.8 mm long in the allpahuayo group). The adaxial horn-like protrusion of the connective at the apex of anthers, characteristic of Curarea iquitana, is variable amongst the studied collections, appearing as a horn (long and weakly incurved), as an apical-adaxial keel or as an adaxial hump, the latter more frequently being observed in the allpahuayo group; anthers are for the most part immersed in the connective. An old and fragmentary pistillate inflorescence of C. iquitanas.s. is a thyrse with brownish or silvery villous indumentum and the rugulose or muriculate drupelets have a golden-brownish velutinous-hispidulous indumentum. The only pistillate inflorescence known in the allpahuayo group has cymose primary branches proximally, distally these being reduced to single flowers giving the appearance of being racemose. The immature condition of the drupelets in most collections studied precludes their use in analyses of quantitative variation of the groups. Collections from non-flooded areas around Iquitos in eastern Peru, ca. 110–140 m in elevation and those from the Andean foothills in Pasco department, from 500–1380 m elevation, are here provisionally included in C. iquitana.

PERU. Amazonas: [Prov.] Condorcanqui, Río Cenepa, Camino Etseketal, norte de Huampami, monte, 600–800 ft, 31 Jul 1974, (♂ fl), Ancuash 660 (MO!, NY!); Prov. Bagua, Distrito Imaza, Región Nororiental del Marañon, Comunidad Aguaruna de Kusú-Listra, Cerro Apág, margen derecha Quebrada Kusú, 05°02'24"S; 078°19'12"W, 600–700 m, 17 Sep 1996, (imm fr), Díaz et al. 8239 (MO!); Rio Cenepa región, monte, orilla de Quebrada Huampami, 18 Jan 1973, (mat fr), Kayap 156 (MO!); Río Cenepa, vicinity of Huampami, ca. 5 km east of Chávez Valdivia, Que Quebrada Najamtai entsa, en bosque primario, 04° 30'S; 78° 30'W, 200–250 m, 3 Aug 1978 (♀ fl & imm fr), Kujikat 107 (MO!); Comunidad de Yamayakat, Río Marañon, bosque primario, 04°55'S; 078°19'W, 320 m, 15 Jul 1994, (♂ fl), Vásquez et al. 18715 (MO!). Loreto: Prov. Maynas, Distrito de Indiana, campamento turístico de Explorama, bosque, 03°30'S; 073°14'W, 110 m, 10 Feb 1996, (♂ fl), Ortiz et al. 167 (MO!); ibid., 11 Feb 1996, (mat. fr.), Ortiz et al. 172 (MO!); Distrito de Iquitos, Estación Experimental de Allpahuayo, IIAP, bosque, 04°10'S; 073°30'W, 120–140 m, 20 Feb 1996, (♂ fl), Ortiz 176 (MO!); ibid., 22 Feb 1996 (♂ fl), Ortiz 181 (MO!); ibid., 23 Feb 1996, (♀ fl), Ortiz 184 (MO!); ibid., 23 Feb 1986, (♀ fl, imm & mat fr), Ortiz 186 (MO!). Pasco: Dist. Palcazu, Comunidad Nativa Alto Lagarto (Reserva Comunal Yanesha), remanente de bosque primario, 10°08'04"S; 075°22'06"W, 500 m, 9 Feb 2011, (mat fr), Rojas & Ortiz 7674 (HOXA n.v., MO!, USM!); Prov. Oxapampa, Parque Nacional Yanachaga-Chemillen, sector Alto Lagarto, remanente de bosque primario, 10°07'44"S; 075°26'41"W, 1380 m, 20 Aug 2011, (imm fr), Rojas et al. 7909 (HOXA n.v., MO!, USM!); Prov. Oxapampa, Gran Pajonal, trail between Chequitavo and Shumahuani, primary forest, 1200–1300 m, 10°45'S; 074°23'W, 30 Mar 1984, (mat fr), Smith 6584 (MO!).

Large canopy lianas about 20–30 m tall; older stems, 5–15 cm wide, strongly flattened; bark dark brown, with shallow lengthwise fissures; branchlets brown to creamy villous. Leaves: blades 9–30 × 7–20 cm, ovate to broadly ovate; chartaceous to subcoriaceous when mature or when directly exposed to sunlight, base truncate, obtuse or shallowly cordate, margin entire, apex acuminate to retuse (cleft in Krukoff 8713), cuspidate when juvenile; surfaces conspicuously discolorous, lustrous and glabrous adaxially, coarsely cream to silvery tomentulose abaxially, matted when older, indumentum concealing the abaxial surface at all stages, (5–)7–9 palmati- or plinerved, innermost pair of main veins acrodromous perfect on mature leaves, acrodromous imperfect on juvenile ones, midrib and lateral nerves slightly impressed adaxially, conspicuously raised abaxially, secondary veins 1–2 pairs, arising above the middle of the blade, sometimes absent, veinlets immersed adaxially, raised abaxially; petioles 4.7–21 cm long, smooth, densely creamy or brownish villous to glabrate, apical pulvinus more conspicuous, rugose, weakly flattened adaxially. Staminate inflorescences solitary or fasciculate, axillary or slightly supra-axillary, thyrsi (Fig. 22A–B), densely brownish or greyish tomentellous; axes 5.7–19 cm long; primary branches 1.1–3.5 cm long, lax, with several (3–6) cymose orders of branching, higher order branching frequently reduced; flowers frequently sessile at the centre of the irregularly further dichotomous branchings; bracts 0.7–1.1 mm long, narrowly ovate, concave, fleshy, glabrous adaxially, brown tomentellous abaxially. Pistillate inflorescences solitary or fascicled, axillary stout thyrsi (Fig. 23B), with dichasial primary branches or these less frequently reduced to single flowers and hence appearing racemiform, densely light brown or greyish tomentellous; axes ca. 5 cm long; bracts ca. 2 mm long, ovate, concave, fleshy, indumentum as on inflorescence. Staminate flowers, 1.2–1.7 mm long, green; pedicels (0–)0.3–3.3 mm long, thick, terete, indumentum as on staminate inflorescence; bracteoles 1–2, 0.2–0.4 × 0.1–0.3 mm, narrowly ovate, fleshy, glabrous adaxially, light brown or creamy tomentellous abaxially; sepals 6; outer sepals 0.4–0.9 × 0.3–0.7 mm, ovate or oblong, indumentum as on bracteoles, base truncate, apex acute; inner sepals 1.1–1.9 × 1–1.7 mm, obovate or ovate-rhombic, mostly light brown or greyish tomentellous abaxially, obtuse at base, apex obtuse or rounded, tip of inner sepals erect or spreading, less frequently reflexed past anthesis; petals 6, 0.4–0.8 × 0.2–0.6 mm, inner ones slightly shorter and narrower, obovate-trilobed or rhombic, weakly concave, membranous, glabrous adaxially and abaxially, base cuneate-truncate, lateral margins inflexed, partially clasping the filaments, apex obtuse, truncate or retuse; stamens 6; filaments 0.2–0.5 mm long, clavate, thick, free or shortly connate at base, glabrous; anthers 0.2–0.3 mm long, erect, connective thicker adaxially forming a keel (Fig. 22 G–H), not overgrowing thecae apically. Pistillate flowers ca. 1.6 mm long, brownish; pedicels ca. (0–)1.7 mm long; terete, indumentum as on pistillate inflorescence; bracteoles 3, ca. 0.4 × 0.2 mm, oblong or ovate, fleshy, glabrous adaxially, brownish tomentellous abaxially; sepals 6, weakly concave, fleshy, indumentum as on bracteoles; outer sepals ca. 0.5 × 0.3 mm, ovate or oblong; inner sepals ca. 1.5 × 0.9 mm, obovate tips erect to reflexed past anthesis; petals 3(4), ca. 0.9 × 0.6 mm, opposed to and/or alternating with the carpels, spatulate, weakly concave, membranous, glabrous adaxially, glabrous to sparsely light brown tomentellous abaxially, clawed at base, apex acute to retuse; carpels 3(4), ca. 0.6 × 0.5 mm, brown tomentose; style ca. 0.4 mm long. Infructescences axes ca. 4 (–6) × 0.3–0.4 cm, indumentum as on inflorescences; fruiting pedicels inconspicuous; carpophores ca. 2.7 × 4.3 mm, subglobose (seen in immature fruits only), brownish to creamy villose. Drupelets ca. 2.9 × 2 cm, ellipsoid to oblongoid (Fig. 23G), conspicuously eccentrically attached, base obtuse, stylar scar not apparent; exocarp 1.8–1.9 mm thick, surface rugose, brownish villous, granular when dried; mesocarp thin and mucilaginous; endocarp 2–2.5 × 1.1–1.5 cm, papyraceous, surface smooth. Seeds with embryo 4–6 cm long, cotyledons slightly unequal.

Figure 22. 

Curarea tecunarum staminate plant: A flowering branch B detail of inflorescence C flower bud D inner sepal, adaxial surface E–F outer and inner petals, adaxial surfaces G–H outer stamens, latero-abaxial and lateral surfaces (A–B based on Krukoff 8713C–H based on Pipoly et al. 12846).

Figure 23. 

Curarea tecunarum pistillate plant: A flowering branch B detail of inflorescence C flower bud D innermost sepal, adaxial surface E petal, abaxial surface F carpels G infructescence (A–F based on Fróes 21446G based on van der Werff & Vásquez 13909).

Lowland Amazonia in Brazil, Colombia, and Peru (Fig. 21 –fertile and only a few sterile ones are mapped), at elevations of 120–300 m (550 m in Bagua, based on Vásquez et al. 19467, a sterile collection from Bagua, in Peru, here identified tentatively) in tropical wet forest. It is also expected in the eastern lowlands of Ecuador (see below). Staminate flowering specimens were collected in February, July and September–November; the only pistillate flowering specimen was collected in November and fruiting specimens were collected in February and March.

(sterile specimens are indicated as st). Brazil: component of curare made by Tecuna Indians, “atinupa” (Krukoff and Smith 1937, Krukoff and Moldenke 1938, Macbride 1938), (Krukoff 7535, st; Krukoff 7578, ♂ fl buds); as ingredient of arrow and dart poison, “bicava” (Prance et al. 13931, st); as ingredient of Jamamadi Indian arrow poison “bicafo” (Campbell et al. P21256, st); as a contraceptive by the Deni Indians, “beku” (Prance et al. 16453, st). Colombia: “taufe-lleida” (Huitoto) (Díaz 10, st); “arrow poison” (Naranjo & Wiederhold 16, st); as curare (Pinkley 392, st); “awa puh”, as ingredient of arrow poison (Bara maku), (Silverwood-Cope 23, st). Ecuador: “oonta”, to make dart poison (Davis & Yost 943, st); “ontame”, hunting, (Huaorani), (Freire & Naranjo 685, st); “oonta”, used to make blowgun dart poison, (Huaorani), (King et al. 972, 977, st); “palahuasca”, as ingredient of curare (Quichua) (Lewis et al. 13848, st); “largancho” (Moya & Reyes 274, st); “zapepa”, employed in arrow poison (Naranjo 7, st); “ontame”, hunting (Huaorani) Naranjo & Freire 363, st); “unta”, hunting (Huaorani) (Naranjo & Freire 635, st); as curare (Pinkley 285, st). Peru: “abuta, abote”, used as vermifugue (Huamán et al. 417, st); “tseás” as ingredient of curare (Mayna Jívaro) (Lewis et al. 10224, st); “macháp” (Mayna Jívaro) (Lewis et al. 10425, st); “machaap”, as main ingredient of curare (Achual Jívaro) (Lewis et al. 11759, st); “macháp” (Achuar Jívaro), “nakaapur, papur” (Achuar Jívaro), medicinal, to treat leishmaniasis lesions, also as ingredient of curare (Lewis et al. 14349, st); “abuta”, to prepare poison for hunting (Martin & Lau-Cam 1204, st); “abuta hembra” (Martin & Lau-Cam 1273, st); “abuta hembra (Mathias & Taylor 3555, st); “abuta” (Mathias & Taylor 5004, 5010, st); “abuta amarilla” (Rimachi 11394, ♂ fl); “abuta ancho” (Schunke 5848, 5849, 5850, and 5851, all st); “abuta amarilla” (Tina & Oliveira 2343, st); “medicinal, (Vásquez 16803, st); “abuta negra” (Woytkowski 5336, st); “ampi” (Woytkowski 5354, 5355, st).

In reference to the Tecuna Indians who used the plant as a source of curare (Barneby and Krukoff 1971),

Specimens from Brazil (Prance et al. 13991 and Campbell et al. P21256) were previously identified as C. toxicofera. Likewise, the common name of “atinupa” attributed to Chondrodendron polyanthum or to Chondrodendron toxicoferum (= Curarea toxicofera) (Krukoff and Smith 1937, Krukoff and Moldenke 1938, Macbride 1938, Barneby and Krukoff 1971) are here confirmed to refer to Curarea tecunarum.

The 14 collections evaluated correspond to 11 localities and yielded an Extent of occurrence (EOO) of 712,212 km² and an Area of Occupancy (AOO) of 44 km². The 11 localities, represent 11 subpopulations and 9 locations, four are found within protected areas (one in Parque Nacional Natural Amacayacu and another in Parque Nacional Cahuinarí, both in Colombia and two in Allpahuayo-Mishana National Reserve in Peru). Additionally, one was found in private lands in Peru. Based on several sterile specimens that are here assigned tentatively (and were not mapped nor included in the conservation assessment), the species appears to be distributed across the Amazon basin, hence the estimated AOO may be greater than that reported here. Therefore C. tecunarum is assigned a preliminary status of “Least Concern” (LC).

Laxly multi-branched staminate inflorescences covered with brownish or creamy tomentellous indumentum and flowers that are usually sessile on irregular higher order branches are unique to C. tecunarum. The species shares with C. barnebyana and C. crassa a tomentellous indumentum on the abaxial leaf surface as well as subglobose carpophores, but the latter two have staminate inflorescences with condensed/contracted primary branches. These species also share some anatomical features (Table 5; discussion of C. crassa).

BRAZIL. Acre: Sena Madureira, Floresta Estadual do Antymari, ramal do Ouro, ca./abbrev> 30 km da sede Úirapuro (Servicio Florestal), 09°19'47"S; 68°18'12"W, 9 Mar 13, (mat fr), Medeiros et al. 1091 (NY!). Amazonas: Igarapé Curucuhy, São Gabriel, 27 Nov 1945, (♀ fl), Fróes 21446 (F!, IAN!, NY!); Munic. São Paulo de Olivença, ibid., near Palmares, 11 Sept 1936–26 Oct 1936, (♂ fl), Krukoff 8370 (A!, BM!, BR!, F [2]!, G!, MO!, NY!, U!). Rio de Janeiro: Cultivated in Rio de Janeiro, no specific locality (st), Glaziou 9610 (P [2]!–a duplicate at F! as “9610” instead = C. toxicofera. Rondônia: Rodovia, Alvorada-Costa Marques, km 90, colectado no transectum, mata de terra firme, solo areno-argiloso, 2 Jul 1983, (♂ fl), Silva 6538 (IAN!, MG!, RB-2!); Margen direita do Río Pacáas Novos, entre a 1ra e 2da cachoeira, mata de várzea, 20 Mar 1978, (imm fr), Ubiratan et al. 218 (GH!, MO!, NY!).

COLOMBIA. Amazonas: La Pedrera, Inspección de Santa Isabel, Parque Nacional Natural Cahuinarí, Estación Biológica Puerto Barbados; várzea (rebalse alta) sobre suelos lateríticos, dominada por Astrocaryum, 01°28'S; 070°46'W, 300 m, 29 Nov 1990, (♂ fl), Pipoly et al. 12846 (MO!, NY!). Comisaría del Putumayo: Between Río San Miguel and Río Guamués, Aug 1963, (st), Naranjo 7 (AMES!). Vaupés: Right tributary of Rio Macu-Parana, 1–8 Jun 1970, (st), Silverwood-Cope 23 (AMES!).

ECUADOR. Napo: Confluence of Quiwado and Tiwaeno Rivers, 13 Apr 1981, (st), Davis & Yost 943 (AMES!). Orellana: Loreto, Reserva Étnica Huaorani, Comunidad Miwaguno a 140 km al. sur del Coca, vía al. Pindo, bloque 14 (ENCAN), Río Shiripuno, 00°43'32S; 076°43'36"W, 250 m, 9 May 2004, (st), Freire & Naranjo 685 (MO!, QCNE n.v.). Pastaza: Kapawí (Amuntai), Río Pastaza, village area, secondary and primary forests and pastures, 02°31'S; 076°48'W, 235 m, 25–29 July 1989, (st), Lewis et al. 13848 (MO!).

PERU. Amazonas: Bagua, Distrito Imaza, Región del Marañon, Comunidad de Yamayakat, Quebrada Kusu-Chapi, Río Marañon, 04°55'S; 078°19'W, 550 m, Feb 1995, (st), Vásquez et al. 19467 (MO!). Loreto: Maynas, Distrito Las Amazonas, Quebrada Sucusari, bosque maduro en tierra firme, 03°15'S; 072°55'W, 140 m, 1 Feb 1996, (imm fr), Ortiz et al. 143 (MO!); ibid., (♂ fl), Ortiz et al. 144 (MO!); Distrito de Iquitos, Estación Experimental de Allpahuayo, IIAP, 04°10'S; 073°30'W, 120 m, 24 Feb 1996, (old ♂ fl), Ortiz & Ruiz 188 (MO!); Carretera Iquitos-Nauta, km 21, trocha de penetración del fundo Pichiri, en terreno alto y arenoso, 150 m, 18 Oct 1995, (♂ fl), Rimachi 11394 (MO!). Pasco: Oxapampa, vivero, Proyecto Pichis Palcazu, Puerto Bermudez, transect 2, 10°12'S; 074°57'W, 200 m, 16 Jun 1983, (st), Gentry et al. 42061 (MO!). San Martin–Ucayali: Vicinity of Aguaytía, high ground in forest, east of Aguaytía, between Pucallpa road and Río Aguaytía, 28 Jun 1960, (st), Mathias & Taylor 5004 (F!). Ucayali: Aguaytía, Fundo Vista Alegre, 29 Mar 1962, (st), Schunke 5848 (F! [2]).

VENEZUELA. Amazonas: Cerro Neblina base camp on Rio Mawarinuma, mature forest on sandy “ultisol”, 140 m, 23 Apr 1984, (st), Gentry & Stein 46878 (MO!).

Small to medium-sized understory lianas about (0.5–)3–10 tall; older stems more or less terete ca. 0.5–1.5 cm diameter; bark greyish to dark brown, with shallow lengthwise fissures and scarcely tuberculate-lenticellate; branchlets greyish to brownish hispidulous. Leaves: blades 7–22 × 5–14 cm, ovate, narrowly ovate or elliptic; membranous when juvenile, chartaceous when mature or when directly exposed to sunlight; surfaces conspicuously discolorous, lustrous and glabrous adaxially, finely silvery tomentellous abaxially, intermixed with some coarser hairs, concealing the surface at all stages, base truncate, obtuse, rounded or shallowly cordate, apex acute, long-acuminate when juvenile, 3(5) palmati- or plinerved, innermost pair of main veins acrodromous imperfect at all stages, midrib shallowly impressed to flat adaxially, conspicuously raised abaxially, secondary veins 2–4 pairs, arising above the middle of the blade, impressed adaxially, raised abaxially, veinlets slightly prominent adaxially, conspicuously raised abaxially, but then concealed by the indumentum; petioles 3–11 cm long, ridged, rufescent or greyish strigillose to glabrate, distal pulvinus moderately conspicuous, rugulose, sometimes weakly flat adaxially. Staminate inflorescences solitary or fascicled, cauliflorous or axillary, thyrsi, densely brownish rufescent or silvery hispidulous, trichomes moderately long; axes 6–15(–25) cm long; primary branches slender, 1.7–3.7(–7.5) cm long, with 2–3(–5) branching orders laxly arranged; bracts 0.7–1.3 mm long, narrow ovate to ovate, concave, ascending, moderately fleshy, glabrous adaxially, brownish, rufescent or silvery villose abaxially, trichomes moderately spreading. Pistillate inflorescences fascicled, cauliflorous, moderately slender, few-flowered thyrsi, these with the primary branches reduced to single flowers, light brown or rufescent hispidulous; axes 4.2(–8.6) cm long; bracts 0.8(–1.2) mm long, ovate, concave, scarcely fleshy, glabrous adaxially, brown tomentellous abaxially. Staminate flowers, 1.2–2 mm long, brownish, greyish, yellowish or greenish; pedicels 0.8–2.8 mm long, terete, thick, indumentum as on the staminate inflorescence; bracteoles 1–4, 0.2–0.4 × 0.2–0.4 mm, ovate, moderately fleshy, glabrous adaxially, rufescent or light golden villose abaxially, trichomes moderately spreading; sepals 6(9), 2(3)–whorled, glabrous adaxially, abaxially with a rufescent to silvery or greyish indumentum, trichomes moderately spreading; outer sepals 0.5–1.1 × 0.4–0.8 mm, ovate or elliptic, base truncate, apex obtuse; (middle sepals 1.2–1.6 x 0.8–0.9 mm, narrow ovate to ovate, base and apex obtuse, moderately fleshy); inner sepals 1.1–2.2 × 1.1–1.7 mm, ovate or elliptic, base obtuse or cuneate, apex acute or obtuse, tip of inner sepals mostly erect past anthesis; petals 6(9), 0.6–1.3 × 0.4–0.9 mm, the inner one slightly smaller and narrower, obovate-trilobed (spatuliform-trilobed), strongly concave, membranous, glabrous adaxially, glabrous to sparsely silvery tomentellous abaxially, base cuneate or distinctly clawed, lateral margin inflexed, partially clasping the filaments, apex obtuse or truncate; stamens 6, filaments 0.4–0.9 mm long, clavate, rarely weakly terete, free (shortly connate at base), glabrous; anthers 0.2–0.3 mm long, erect, connective frequently thinner apically, thecae splitting into two halves, connective thicker adaxially (protruding as a hump at the base or at the apex of thecae). Pistillate flowers ca. 1.8 mm long, yellowish to brownish; pedicels ca. 6.4 mm long, terete, indumentum as on the pistillate inflorescence; bracteoles 2, ca. 0.4 × 0.3 mm, ovate, weakly concave, fleshy, glabrous adaxially, brownish, silvery or rufescent villous abaxially, trichomes moderately spreading; sepals 6–9, weakly concave and scarcely fleshy, in 2–3 whorls, indumentum as on bracteoles; outer sepals ca. 0.5 × 0.4 mm, ovate, base truncate, apex acute or obtuse; (middle sepals, ca. 0.9 × 0.8 mm, ovate to broadly ovate, base and apex obtuse); inner sepals ca. 1.5 × 1.4 mm, elliptic, apex and base obtuse, tips erect to weakly reflexed past anthesis; petals 3(6), ca. 1.2 × 0.7 mm, spatulate, weakly concave, membranous, glabrous adaxially and abaxially, base cuneate or clawed, apex obtuse, (when six petals, the inner ones usually narrower); carpels 3(4), ca. 0.6 × 0.3 mm, pilose; style ca. 0.6 mm long. Infructescences moderately slender, rufescent, brownish or silvery villous, indumentum spreading; axes 1.7–6 × 0.2–0.5 cm; fruiting pedicels (of mature fruits only) 0.4–1.6 cm long, terete; carpophores 4.1–10.6 mm long, free, clavate or terete, brownish-silvery velutinous. Drupelets 1.3–2.4 × 0.8–1.5 cm, dull orange to yellow when ripe, oblongoid or ellipsoid, eccentrically attached, shortly stipitate, base attenuate or truncate, stylar scar usually conspicuous; exocarp 0.7–1.5 mm thick, surface usually strongly muriculate, brownish to greyish hispidulous; mesocarp mucilaginous; endocarp 1.3–2.5 x 0.7–1.2 cm, papyraceous, surface weakly reticulate by slightly prominent fibers throughout. Seeds with embryo 2.6–4.4 cm long, cotyledons equal.

The species ranges from eastern Ecuador (Napo Prov.) through central-southern Peru (Huánuco, Madre de Dios, Puno, San Martín and Ucayali departments), northern Bolivia (Beni, La Paz, and Pando) to western Brazil (Acre and Rondônia) (Fig. 25). It occurs mostly on non-flooded forest, from about 71 m in Acre (Brazil) up to 1550 m elevation in Franz Calabatea (Bolivia).

Figure 24. 

Curarea tomentocarpa (photograph of the type of Cissampelos tomentocarpa, Williams 616, NY).

Figure 25. 

Geographic distribution of Curarea tomentocarpa and C. toxicofera.

Bolivia: “betchusajaja” (Tacana name), and “huevo de mono” (Spanish name), fruits edible when ripe (DeWalt et al. 865, imm fr); “chocolatillo” (Perry et al. 654, st); “uvilla”, fruit edible, but astringent (Smith et al. 12882, mat fr). Brazil: “cipó cacau” (Portuguese) (Daly et al. 9172, ♂ fl); “cipó cacauí” (Daly et al. 9233, imm fr; 11472, imm fr). Ecuador: “curare” (Palacios et al. 881, ♂ fl); “chichico huasca” (Kichwa), fruits edible (Reyes & Carrillo 827, mat fr; Carrillo & Reyes 695, mat fr). Peru: “ampihuasca amarilla” (Schunke 2981, mat fr); “ampihuasca delgadito” (Schunke 6836, ♂ fl, MO sheet sterile); “ampihuasca negra” (Schunke 7125, ♂ fl).

Possibly in reference of the hispidulous-muriculate surface of the drupelets which is frequently described as warty in herbarium specimens.

The Extent of Occurrence (EOO), calculated for the 67 collections corresponding to 45 localities of C. tomentocarpa, is 984,251 km² and its Area of Occupancy (AOO) is 176 km². Although the species is not abundant where it occurs and, of the 39 subpopulations, 10 are found within protected areas across its distribution in Bolivia, Ecuador and Peru. This suggests that its AOO may be larger than the one estimated here; therefore, C. tomentocarpa is assigned a preliminary category of “Least Concern” (LC).

The species is distinguished by its staminate inflorescence with densely brownish, rufescent or silvery hispidulous, moderately long and spreading indumentum and by the anthers with thin connective that the former frequently split into two halves. The only pistillate inflorescence available in this study has the primary branches reduced to single flowers, thus appearing racemiform. However, fruiting specimens from the same areas, that are similar in other features, appear to be clearly thyrsoid. It is likely that the inflorescence becomes more differentiated during further development, but that has not been confirmed here. The drupelets are always strongly muriculate. However, a single fruiting collection from Huánuco in central Peru (Schunke 2981) has a smooth surface and velutinous indumentum, although no pistillate flowers from the area were available in this study. The quantitative characters evaluated here in a few staminate plants from San Martín (Gentry 25720; Schunke 6836, 7125) and from Ucayali (Schunke 2690) that resemble, in leaf shape and indumentum, the fruiting specimen mentioned above, completely overlap with those of tomentocarpa (Fig. 11B). Hence, I am unable to match variation in the staminate specimens to that in the fruiting material. Therefore, all of these collections are here provisionally placed under C. tomentocarpa.

BOLIVIA. Beni: Vaca Diez, 9.2 km N from the road between Riberalta and Guayaramarín, on the old road to Cachuela Esperanza, primary forest, 11°05'S; 065°50'W, 230 m, 18 Sep 1981, (mat fr), Solomon 6317 (MO!, NY!). La Paz: Franz Tamayo, Parque Nacional Madidi, laguna Chalalan, senda Jaguar, bosque amazonico preandino, 14°25'30S; 067°55'16"W, 300 m, 26 Sep 2006, (mat fr), Araujo-M. et al. 3131 (LPB n.v., MO!, NY n.v.); Abel Iturralde, Comunidad de Buena Vista, parcela permamente de estudio etnobotánico, 3 km al. NE de Buenavista, 14°22'S; 067°33'W, 180 m, 12 Apr 1995, (imm fr), DeWalt et al. 865 (MO!); Parque Nacional y Area de Manejo Integrado Madidi, Laguna Chalalán, entrando 45 min., sobre orilla izquierda de Río Tuichí, vegetación borde de laguna, dominada por Mauritia flexuosa y helechos arbóreos, 14°26'S; 067°55'W, 450 m, 23 Apr 1997, (mat fr), Paniagua & Beck 1171 (LPB n.v., MO!). Pando: Manuripi, Carretera entre Cobijá y Chicé km al. S del Río Manuripi, 11°55'S; 068°36'W, 200 m, 1 Oct 1991, (mat fr), Perry et al. 413 (LPB n.v., MO!).

BRAZIL. Acre: Mun. Sena Madureira, basin of Rio Purus, Rio Macauã, Colocacãa Apuí, river descending, 3 m below high water mark, terra firme forest on poorly drained soil, undulating terrain dissected by numerous streams, 09°48'S; 069°11'W, 29 Mar 1994, (imm fr), Daly et al. 8073 (MO!, NY! [image seen]); Rio Acre, Antimary, Jul 1904, (fr), Huber 4286 (B! frag., MG, n.v.); Km 16 from Rio Branco on Rio Branco-Brasiléia road, 20 Oct 1980, (♂ fl), Lowrie et al. 595 (NY!, US [2]!); Estrada Rio Branco-Brasiléia, km 42, mata primaria de terra firme, 10°00'S; 067°50'W, 16 Oct 1980, (mat fr), Nelson 716 (NY!).

ECUADOR. Napo: Tena, Estación Biológica Jatun Sacha, bosque muy húmedo tropical, suelo principalmente compuesto por arcilla roja, 01°04'S; 077°36'W, 450 m, 29 Jun 1996, (imm fr), Ortiz & Vargas 197 (MO!); ibid., 3 Jul 1996, (♂ fl), Ortiz & Vargas 199 (MO!); Río Arajuno, Sola Cocha, bosque muy húmedo tropical, suelo rojo arcilloso (ultisol), colinas pendientes, 01°07'S; 077°36'W, 500 m, 23–27 Oct 1985, (♂ fl), Palacios et al. 881 (AAU n.v., MO-2!, NY!, QCA n.v., QCNE n.v.); Estación Biológica Jatun Sacha, bosque muy húmedo tropical, bosque primario sobre suelos rojos de colinas, 01°04'S; 077°37'W, 450 m, 06–14 Oct 1988, (♂ fl), Palacios 3106 (MO!, NY!).

Orellana: Reserva Florística El Chuncho, 5 Km al. norte de Coca, bosque húmedo tropical, suelos rojos sobre colinas disectadas, parcela permanente, 00°25'S; 077°01'W, 250 m, 23 May 1993, (mat fr), Palacios 10725 (MO!, QCNE n.v.); Aguarico, Parroquia Capitán Agusto Rivadeneira, comunidad Chiro Isla (Kichwa), bosque de matorrales, 00°37'28S; 075°51'31"W, 200 m, 22 Feb 2005, (mat fr), Reyes & Carrillo 827 (MO!, QCNE n.v.).

PERU. Cusco: La Convención, Río Manguriari (Manguyari), Tropical Forests –Alto Urubamba; upstream to Río Manguriari, forest edge, 12°47'S; 072°40'W, 750 m, 2 Feb 1991, (st), Núñez & Ortíz 12765 (MO!). Huánuco: Pachitea, Dtto. Puerto Inca, Bosque Nacional de Iparia, región de bosque seco tropical a lo largo del Río Pachitea, cerca del pueblo de Puerto Inca (unos 85 km en distancia lineal de la confluencia con el Río Ucayali), 12 Jan 1969, (mat fr), Schunke 2981 (F!, G!, NY!, US!). Madre de Dios: Manu. Parque Nacional de Manu, in forest near Cocha Cashu Station, on an old ox-bow lake of the Rio Manu, 11 Aug 1973, (mat fr), Foster 2543 (NY!); Vicinity of Cocha Cashu, 400 m, 4 Aug 1977, (mat fr), Foster & Terborgh 6480 (F!, NY!); Trails 4, 5 and 9, Cashu Cocha Camp, Manu National Park, non-inundated forest on alluvial soil, 380 m, 21 Oct 1979, (♀ fl), Gentry et al. 27080 (F!, MO!, NY!); Tambopata Reserve, Río Tambopata at mouth of Río D’Orbigny, non-transect, [12°50'S; 069°17'W], 200 m, 2 Mar 1981, (imm fr), Gentry & Young 31927 (MO!, USM n.v.); Zona reservada de Tambopata, 12°49'S; 069°18'W, 280 m, 10 Aug 1990, (imm fr), Reynel & Meneses 5025 (MO!); Dist. Puerto Maldonado, Cusco Amazónico, bosque Primario, 250–300 m, 13°08'S; 069°36'W, 22 Nov 2002, (♂ fl), Valenzuela et al. 975 (CUZ, n.v., MO!, USM, n.v.). Puno: Carabaya, Cabeceras del Río Candamo, 550–600 m, 13°15'S; 070°02'W, 24 Oct 1996, (mat fr), Cornejo 2650 (MO!, fruit not seen); Río Candamo, fila at mouth of Río Guacamayo, ridge top forest with cloud forest aspect, 13°30'S; 069°50'W, 800 m, 26 May 1992, (imm fr), Gentry et al. 77256 (MO!). San Martin: Fundo Curareland near Tinanta, 20 km NW of Tocache, at N edge of palm plantation, mature forest and forest edge, on alluvial soil near Rio Huallaga, 08°06'31"S; 076°3314"W, 500 m, 14 Mar 1979, (♂ fl), Gentry et al. 25720 (F!, MO!, NY!, USM!); Mariscal Caceres, Dtto. de Tocache Nuevo, Santa Rosa de Mishollo (margen derecha del Rio Mishollo), 500 m, 15 Aug 1976, (♂ fl), Schunke 6836 (MO!, NY!); Quebrada de Huaquisha (margen derecha del Rio Huallaga), 450 m, 2 Jul 1974, (♂ fl), Schunke 7125 (F!, MO!, USM!). Ucayali: Coronel Portillo, Vicinity of LSU base camp, Quebrada Shesha (tributary of Río Abujao), ca. 65 km NE of Pucallpa, 08°02'S; 073°55'W, 250 m, 25 Jun 1987, (imm fr), Gentry & Díaz 58512 (F!, MO!); [Distrito de] Iparia, a lo largo del Río Ucayali, cerca del pueblo de Iparia (unos 80 km arriba de la confluencia con el Río Pachitea), 300 m, 26 Aug 1968, (♂ fl buds & fl), Schunke 2690 (F!, G, NY!); Dtto. Purús, Rio la Novia, margen derecha del caserio de la comunidad nativa San José, bosque alto, terreno húmedo, 10°12'S; 070°57'W, 180 m, 13 Feb 2002, (mat fr), Schunke & Graham 14779 (MO!).

Medium-sized understory lianas about 10–12 m tall; older stems more or less terete or less frequently flattened, then ca. 3 cm wide; bark greyish to dark brown, with shallow lengthwise fissures; branchlets brownish, greyish to silvery puberulent-strigillose. Leaves: blades 8–24 × 5–17 cm, narrowly to broadly ovate, chartaceous at all stages; surfaces discolorous, lustrous and glabrous adaxially, finely silvery tomentellous abaxially, sometimes creamish when older, indumentum mostly concealing the surface at all stages, base truncate, obtuse or shallowly cordate, apex acute or acuminate, long-acuminate when juvenile, 3–5(–7) palmati- or shortly plinerved, innermost pair of main veins acrodromous imperfect at all stages, midrib adaxially shallowly sunken at the base, becoming flat, conspicuously raised abaxially, secondary veins 2–3(–5) pairs, arising above the middle of the blade, raised on both surfaces, more conspicuous abaxially, veinlets slightly prominent adaxially, more conspicuous abaxially; petioles (2.7–)6–25 cm long, ridged, brownish to silvery strigillose-tomentellous or glabrate, distal pulvinus more conspicuous, rugulose, rounded, sometimes more or less flat adaxially. Staminate inflorescences solitary or fascicled, cauliflorous or axillary thyrsi, brownish, greyish or silvery strigillose-tomentellous, (trichomes spreading); axes, 10–42 cm long (less frequently simple dichasia arising in young terminal shoots, then the dichasia axes 2–4 cm long) (Fig. 26A), densely brown; primary branches 1.4–9.4 cm long, with several (2–4) branching orders, these laxly arranged; bracts 0.5–1.2 mm long, narrow ovate to ovate, concave, moderately fleshy, indumentum as on the inflorescence. Pistillate inflorescences solitary or fascicled, cauliflorous, moderately stout, few-flowered thyrsi (Fig. 27A), brownish strigillose- tomentellous; axes ca. 2.5 cm long; primary branches 0.7 cm long; bracts ca. 0.8 mm long, ovate, concave, moderately fleshy, glabrous adaxially, brown strigillose-tomentellous abaxially. Staminate flowers 1.6–2.4 mm long, greenish, green-yellowish or whitish; pedicels 1.6–6.0 mm long, mostly slender, ridged, indumentum as on staminate inflorescence; bracteoles 1–2, 0.2–0.6 × 0.1–0.4 mm, ovate, moderately fleshy, glabrous adaxially, greyish or silvery villous-tomentellous abaxially; sepals 6, glabrous adaxially, greyish or silvery villous-tomentellous abaxially; outer sepals 0.5–1.4 × 0.3–0.8 mm, narrowly ovate or elliptic, base truncate, apex obtuse; inner sepals 1.5–2.4 × 0.8–1.8 mm, elliptic, ovate, oblong or weakly obovate, base obtuse, cuneate or shortly clawed, apex acute or obtuse, tips mostly strongly reflexed past anthesis; petals 6, 0.7–1.6 × 0.6–1.1 mm, inner ones slightly smaller and narrower, obovate-trilobed or spatulate, weakly concave, membranous, glabrous adaxially, sparse silvery tomentellous abaxially, base cuneate or distinctly short- to long-clawed, lateral margins inflexed, partially clasping the filaments, apex obtuse or truncate; stamens (5)6, filaments 0.3–)0.7–1.4 mm long, clavate or clavate-sigmoid, free (shortly connate), glabrous adaxially, glabrous to mostly silvery tomentellous abaxially; anthers 0.3–0.6 mm long, erect or weakly incurved, especially when older, connective thicker adaxially and protruding as a hump (Fig. 26G) or as a keel at the base of thecae (also apically); thecae not separating apically and, for the most part, not immersed in the connective. Pistillate flowers ca. 2.1 mm long, green; pedicels ca. 1.1 mm long, ridged, brown strigillose-tomentellous; bracteoles 3, ca. 0.4 × 0.3 mm, ovate, fleshy, weakly concave, glabrous adaxially, brownish villose-tomentellous abaxially; sepals 6–9, weakly concave and slightly fleshy to fleshy, glabrous adaxially, brownish, greyish to silvery villous-tomentellous abaxially; outer sepals ca. 0.7 × 0.6 mm, ovate, base truncate, apex acute; middle sepals ca. 1.6 × 1.8 mm, ovate to broadly ovate, base truncate, apex acute, inner sepals ca. 2.0 × 1.3 mm, broadly ovate, obovate, spatulate, elliptic or rhombic, base obtuse or truncate, apex acute or rounded, tips strongly reflexed past anthesis; petals 3, ca. 1.6 × 1.5 mm, spatulate, membranous, weakly concave, glabrous adaxially, moderate silvery tomentellous abaxially, clawed at base, apex obtuse or retuse; carpels 3, ca. 0.7 × 0.7 mm, brown villous tomentellous; style ca. 0.7 mm long. Infructescences axes (2–)8 × 0.3–0.7cm, indumentum as on pistillate inflorescences; fruiting pedicels 1.3–3.5 mm long, terete, slender to moderately stout; carpophores 3.8–11.3 mm long, free or basally connate up to 1/3 of their lengths, claviform or terete, spreading or incurved distally, brown velutinous-hispidulous. Drupelets 1.8–2.1 × 0.9–1.3 cm, dull orange to yellowish when ripe, oblongoid, ellipsoid or subglobose (Fig. 27F), eccentrically attached, base attenuate or truncate, (shortly stipitate); stylar scar conspicuous; exocarp 0.6–0.8 mm thick, surface smooth, rugulose or weakly muriculate, silvery to greyish velutinous; mesocarp mucilaginous; endocarp 0.7–0.9 × 1.5–1.8 cm, papyraceous to chartaceous, smooth, with slightly prominent fibres or weakly rugulose throughout. Seeds with embryo 3.2–4 cm long, cotyledons equal.

Figure 26. 

Curarea toxicofera staminate plant: A flowering branch B detail of inflorescence C flower bud D inner sepal, adaxial surface E–F outer and inner petals, abaxial and latero-adaxial surfaces G–H outer stamens, lateral and abaxial surfaces (A–B based on Ule 5631C–H based on Encarnación 1094).

Figure 27. 

Curarea toxicofera pistillate plant: A flowering branch B flower bud C innermost sepal, adaxial surface D petals and carpels E petal abaxial surface F infructescence (A–E based on Gentry et al. 21624F based on Revilla et al. 2566).

In north-western Amazonia, including the eastern slopes of the Andes in Peru (Fig. 25). The species commonly grows in periodically flooded forests, but also in non-flooded lowland forests and up to 350 (500) m in elevation. Flowering and fruiting material were collected all year round.

(sterile specimens are indicated as st). Brazil: fruits edible (Fróes 26364). Colombia: “taufe-lleida” (Diaz 36, st); “Ñamitá” (en Karijona) (García-Barriga 14578, st); cure for fevers, antimalarial (Grassl 10076, st); said to be “formerly used by Karijona Indians in arrow-poison” (Krukoff and Barneby 1970) (Schultes 5526, st). Ecuador: to hunt wild animals, “ambi-huasca” (Quichua) (Cerón et al. 39668, st). Peru: “pani’ (Castelnau s.n.,1851); “abuta amarilla, “isaveño” (Huitoto) (Martin & Lau-Cam 1266, st); “ampihuasca” (Mathias & Taylor 3900, imm fr); “abuta amarilla” (Rimachi 10636, mat fr; Tina & Tello 2066, ♂ fl); “sarívana” (Weiss 132, st); “ampihuasca”, medicinal (Woytkowski 108, st); “ampihuasca” (Woytkowski 5108, st); “abuta negra” (Rimachi 10503, st).

Sterile collections such as Fox 12 (K), from Peru and Schultes 3522 from Colombia, had previously been identified as Chondrodendron toxicoferum (= Curarea toxicofera) (Krukoff and Barneby 1970), the first being reported as “poison used for blow pipe” and the second as a source of curare with the common name of “sa pe pa” (Kofán) (Krukoff and Barneby 1970). Both specimens cannot be determined with certainty and are here tentatively identified as Curarea sp.

Presumably in reference to the toxic effects attributed to the plant, as the type specimen was collected in the Pevas region, amongst the Yaguas who use the plant in the preparation of arrow poison (de Castelnau 1851: 22).

The Extent of Occurrence (EOO), based on 34 collections corresponding to 28 localities of C. toxicofera, is calculated as 419,469 km² and an Area of Occupancy (AOO) of 108 km². The 28 localities correspond to 27 subpopulations, of which two are within protected areas in Ecuador and four subpopulations are found in private reserves near Iquitos, Peru. In addition the species is widespread across its distribution. Therefore, C. toxicofera is assigned a preliminary category of “Least Concern” (LC).

The typical form of C. toxicofera as circumscribed here, ranges from the Amazonian lowlands of Ecuador, Colombia, Peru and Brazil (including the sterile type specimen of Cocculus toxicoferus Wedd., Castelnau s.n., Peru and the type of Hyperbaena polyantha Diels, Ule 5631, Brazil).

Individuals are frequently found in periodically flooded forests, but can also be found in non-flooded forests up to 500 m in elevation. Most have ovate leaves with 5 main veins and staminate and pistillate inflorescences with very short, brownish to greyish, appressed indumentum, but slightly longer (up to 0.3 mm long) and silvery or cream indumentum is also observed in specimens from the lower Amazon basin in Brazil (e.g. Prance 11272, Fróes 29639 and Ducke 2134).

In the staminate condition, C. toxicofera is readily distinguished from C. tomentocarpa by its brown strigillose-tomentellous indumentum (vs. a rufescent to silvery hispidulous) and its larger flowers –they are the largest in the genus– with greyish to silvery villous-tomentellous, adpressed indumentum (vs. rufescent or silvery spreading indumentum). However, separation from C. iquitana is more challenging and at present is distinguished by its slender pedicels in staminate flowers (vs. thicker in C. iquitana). However, more field and taxonomic work remains to be done in order to be able to confidently match the staminate and pistillate specimens of the taxa involved.

Chondrodendron bioccai is here included in the synonymy with hesitation. As discussed by Krukoff and Barneby (1970), the species appears to have been described from two collections (from the region of Rio Tiquiê and the region of Rio Uaupés by Biocca and Giacone, respectively). A holotype was not stated, two photographs (listed as Figs 15, 16, but published as Figs 1, 2) presumably of the original material were published in the protologue (Lusina 1954). Krukoff and Barneby (1970) hesitantly placed Chondrodendron bioccai as a synonym of Chondrodendron toxicoferum and later as a synonym of Curarea toxicofera (Barneby & Krukoff, 1971). The repository of the type collection remains uncertain at the present time and hence the taxonomic identity cannot be established firmly.

BRAZIL. Acre. Proje. RADAM-Sub-base de Cruzeiro do Sul-Ponto 7-Sb-18-ZD, 23 Feb 1976, (imm fr), Marinho 291 (NY!). Amazonas: Paraná do Careiro (Boca do Solimões), (varzea, igapó do Lago Capitari), 8 Jun 1948 (♂ fl), Ducke 2134 (COL!, GH!, NY!, R!); Mun. Eirunepe, Lago Dois Unidus, Ituxy, restinga, 30 Nov 1946, (♂ fl), Fróes 21802A (NY!); Beira do lago de Badajós, igapó, 24 Ago 1950, (imm fr), Fróes 26364 (IAN!); Vicinity of Manaus, Igarapé Ipixuna, Lower Rio Negro opposite Manaus, Igapó, 1 Apr 1971, (♂ fl), Prance, et al. 11272 (F!, MG!, NY!, US!). Rondônia: Esperança (ad ostium fluminis Javari), silva loco alto, high forest, 27 Oct 1945, (♂ fl bud), Ducke 1968 (NY!, R!); Rio Machado, curso inferior, igapó, Jan 1981, (♂ fl), Goulding 1187 (MG!).

COLOMBIA. Amazonas: Quebrada El Mochilero, afluente del Yarí, márgenes y zona de rebalse aluvial, 150 m, 24 Apr 1986, (imm fr), Galeano et al. 1135 (COL!); Río Caquetá, La Pedrera, 1–4 Oct 1952, (st.), García-Barriga 14578 (COL!, MO!); Puerto Nariño, Trocha de Panduro a San Martin, bosque no inundable, 03°50'S; 070°20'W, 100 m, 24 Feb 1993, (♂ fl), Madriñán 702 (MO!); Leticia, Parque Nacional Natural Amacayacu, Centro Administrativo Mata-matá (Inderena), a orillas de la quebrada Mata-matá en zona de várzea, 03°47'S; 070°15'W, 100 m, 11 Mar 1991, (imm fr), Rudas et al. 1528 (MO!); Corregimiento de Tarapacá; Caño Pupuña (afluente del Río Cotuhé), a las orillas del caño, 02°59'S; 070°02'W, 100 m, 25 Jun 1991, (♂ fl), Rudas et al. 2512 (MO!). Vaupés: Mayaca River, vicinity of Cachivera del Diablo and mouth of river, 300 m, 1 May 1943, (mat fr), Schultes 5526 (AMES!).

ECUADOR. Napo: Rio Yasuni, periodically inundated forest, ca. 80 km upriver from Nuevo Rocafuerte, 225 m, 17 Sep 1977, (♂ fl bud & fl), Foster 3722 (F!). Orellana: Cantón Nuevo Rocafuerte Isla aproximadamente 10 Ha. entre la Laguna de Jatun Cocha, cerca del Río Yasuní, Parque Nacional Yasuní, Igapó, 00°01'S; 075°28'W, 280 m, 17 Sep 1999, (st), Cerón et al. 39668 (MO!). Pastaza: Curaray, SE of the airstrip, rain forest and Mauritia várzea, understorey dominated of Melastomataceae, Rubiaceae and palms, 01°22'S; 076°57'W, 250 m, 20 Mar 1980, (mat fr), Holm–Nielsen et al. 22169 (AAU n.v., NY!). Sucumbíos: Lago Agrio, Reserva Cuyabeno, Río Cuyabeno, 2-3 km arriba de Laguna Grande, área inundada estacionalmente por aguas negras, 00°00'S; 076°14'W, 230 m, 16 Nov 1991, (♂ fl), Palacios et al. 9032 (MO!); Río Zábalo, bosque húmedo tropical, bosque afectado por inundaciones de aguas negras, 00°22'S; 075°45'W, 230 m, 22 Nov 1991, (imm fr), Palacios et al. 9493 (MO!, NY!).

PERU. Loreto: Yanamono, campamento Explorama Lodge, terreno de altura, 03°25'S; 072°45'W, 120 m, 31 May 1979, (mat fr), Díaz et al. 1187 (MO!); Requena, Caño Yarina, a 300 m de la Base Yarina en la Zona Reservada del Río Pacaya, margen izquierda del Río Ucayali, bosque inundable, 6 Apr 1977, (♂ fl), Encarnación 1094 (G!, MO!, NY!, US!); Rio Itaya, inundated tahuampa forest, [03°46'S; 073°15'W], 120 m, 20 Mar 1977, (♂ fl), Gentry et al. 18505 (F!, MO!, NY!); Maynas, tahuampa near Río Amazonas between Punchana and Santa Clara de Nanay, outskirts of Iquitos, 120 m, 3 Feb 1978, (♀ fl & imm fr), Gentry et al. 21624 (F!, MO!); Alto Amazonas, Balsapuerto (lower Rio Huallaga basin); dense forest, [05°49'S; 76°33'W], 150–350 m, 28–30 Aug 1929, (♂ fl), Killip & Smith 28665 (F!, NY!); Alto Amazonas, Fortaleza, near Yurimaguas, [05°54'S; 76°07'W], 140 m, Nov 1932, (♂ fl), Klug 2782 (BM!, F!, G!, GH!, K!, MO, NY!, US!); Distrito Las Amazonas, Quebrada Sucusari, bosque maduro en tierra firme, camino de ACEER hacia el Napo, 03°15'S; 072°55'W, 140 m, 4 Feb 1996, (♂ fl), Ortiz et al. 157 (MO!); Distrito Iquitos, Rio Itaya, San Juan de Muniches, borde de purma, 16 Oct 1976, (mat fr), Revilla & Carillo 1501 (F!, MO!, NY!); Indiana, Yanamono, Explorama Lodge, Bosque inundable estacional (aguas blancas), 106 m, 03°28'S; 072°50'W, 19 Feb 1989, (♂ fl), Vásquez & Jaramillo 11714 (MO!); Explor Napo Camp at Río Sucusari, primary forest, flooded forest, collected from canoe along Río Sucusari, 03°20'S; 072°55'W, 120 m, 22 Mar 1996, (♂ fl buds & fl), van der Werff & Vásquez 13990 (MO!). Ucayali: Prov. Coronel Portillo, Distrito Calleria, Quebrada Pumayacu, margen izquierda del Río Utiquinia, al. borde de la quebrada, en bosque alto, 150–175 m, 08°09'S; 074°15'W, 13 Ma 2003, (♂ fl bud & fl), Schunke 15323 (F n.v., MO!).

VENEZUELA. Amazonas: Embanchure du Guaviare, Plantes du Haut Orenoque, 1887, (♂ fl), Gaillard 184 (P!); Forest immediately behind “El Tobogan de La Selva” camping area; 35 km south of Puerto Ayacucho, 85 m, 21 Feb 1979, (st), Plowman 7712 (F!).