Curarea candicans (Rich. ex DC.) Barneby & Krukoff

Ortiz, Rosa del C., 2018, A taxonomic revision of Curarea Barneby & Krukoff (Menispermaceae), PhytoKeys 100, pp. 9-89 : 24-30

2. Curarea candicans (Rich. ex DC.) Barneby & Krukoff Figs 13A , 14

Curarea candicans (Rich. ex DC.) Barneby & Krukoff, Mem. New York Bot. Gard. 22(2): 12. 1971.

Abuta candicans Rich. ex DC., Syst. 1: 543. 1818. Type: French Guiana. Cayenne: "Cayensibus dicitur, genus affine Cissampelos ", no date [1781-1789], (sterile), L.C. Richard s.n. (lectotype, designated here [or perhaps holotype]): P-Jussieu Herbarium 10832, photocopy of microfiche P!, IDC microfiche 6206. 803.I). Guyana. Demerara: Mabura Hill Concession, ridgetop ecotone between Wallaba and Purpleheart forest, 05°25'N; 058°40'W, 50 m, 20 Nov 1986, (♂ fl), Pipoly & Boyan 8982 (epitype, designated here: MO!; isoepitypes: NY!, US!). Note: Following Art. 9.8 of the Melbourne Code ( MacNeill et al. 2012), I am here designating an epitype to serve as an interpretative type of Abuta candicans , whose sterile condition makes it ambiguous for identification purposes.

Sciadotenia candicans (Rich. ex DC.) Diels, in Engl. Pflanzenr. 4(94): 87. 1910. Type: Based on Abuta candicans Rich. ex DC.

Chondrodendron candicans (Rich. ex DC.) Sandwith, Bull. Misc. Informat. Kew. 1930: 342. Type: Based on Abuta candicans Rich. ex DC.

Cocculus dichroa Mart., Flora 24, Beibl. II: 46. 1841. Type: Brazil. Para: Habitat in silvis, no date, (sterile), Martius s.n. (lectotype, designated here: M! [image seen]; isolectotype: B! frag., likely of M).

Sciadotenia leucophylla Miers, Contr. Bot. 3: 344. 1871. Type: In Guiana [Guyana]. Guiana Batavana: no date, (sterile), Anderson s.n. (holotype: BM! [BM000071492]).

Abuta limaciifolia Diels, in Engler, Pflanzenr. IV.94(Heft 46): 194. 1910. Type: Brazil. Para: Peixe Boi, [25] July 1907, (♂ fl bud), Rodr. Sigueira s.n. [ Herbário Amazônico Museu Paraênsis (Museu Goeldi) MG-8266], (lectotype designation effected by Krukoff and Moldenke 1938: 20: B!, F neg. 4993; isolectotypes: BM! [BM000071503], MG! [image seen]). Note: The F negative of B specimen has two annotations, one at the bottom right that reads: Abuta limaciifolia Diels and a second one to the bottom left that reads: " Anomospermum limaciifolium Diels sp. nov.", a non-published name, this later annotation is missing in the B specimen available in this study, which may suggest that this second annotation label was not glued-down or the existence of another specimen at B. However, the B specimen I studied appears in every other feature to be the source of the F photograph. Additionally, the measurements included in the original description of the species, suggest that Diels did not examine the duplicates at BM and MG, hence the lectotype designated is the B specimen examined here. The citation by Diels of “Herbário Amazônico Museu Paraênsis” is in reference to the label of the material in B, not to a sheet in MG.

Chondrodendron limaciifolium (Diels) Moldenke, in Krukoff & Moldenke, Brittonia 3: 20. 1938. Type: Based on Abuta limaciifolia Diels.

Abuta (?) Abuta pullei Diels, Rec. Trav. Bot. Neerl. 22: 348. 1925. Type: Suriname. Without locality, 4 Sep 1920, (sterile), Pulle 408 (lectotype designation effected by Krukoff and Moldenke 1938: 18: U! [U-30956, photographs at F!, G!, GH!, MO!; isolectotypes: B!, frag., U! [U-30955]). Note: the original material of Abuta? pullei comprises juvenile leaves and is mounted on two sheets at U. Both appear to have Diels’ handwriting and the sheet U-30956 has one, more or less, complete leaf and two fragmentary leaves. The second sheet, labelled as U-30955, is a much younger leaf and it appears that its measurements were not included in the description of the species. Hence the U-30956 specimen has been considered the holotype and annotated as such by previous authors, a designation that is followed in this study.

Description.

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.

Distribution and ecology.

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.

Common names and uses.

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).

Etymology.

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

Conservation status.

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).

Discussion.

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 usu ally 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 .

Specimens examined.

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!) .

Figures

Figure 9. Geographic distribution of Curarea barnebyana, C. candicans, C. crassa, C. cuatrecasasii and C. gentryana.

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]).