Rhynchosia erythrinoides Schltdl. & Cham.

Bezerra, Luísa Maria De Paula Alves, Cândido, Elisa Silva, Vargas, Wanderleia De, Torke, Benjamin Marland, Lewis, Gwilym Peter & Perez, Ana Paula Fortuna, 2024, Taxonomic revision of Rhynchosia Lour. (Leguminosae, Papilionoideae, Phaseoleae) in South America, Phytotaxa 643 (1), pp. 1-67 : 30-31

10. Rhynchosia erythrinoides Schltdl. & Cham. , Linnaea 5: 587. 1830. Type:— MEXICO, “Inter Misantlam et Nantlam in sylvis”, March 1829 (fr.), C. J. W. Schiede & F. Deppe s.n. (Lectotype, designated by Ståhl et al. [2016]: HAL 0098589 [digital image!]; isolectotypes: BM 000799992 [digital image!], HAL 0107630 [digital image!] LE 00002544 [digital image!]). ( Figs. 4 D–E ; 6 H–I )

Leycephyllum micranthum Piper, J. Wash. Acad. Sci. 14(15): 364. 1924. Type: COSTA RICA. Las Vueltas, Tucurrique, January 1899 (fl.) A. Tonduz 12951 ( Holotype: US 00004550 [digital image!]; isotypes: BAB 00000489 [fragment] [digital image!], BM 000799991 [digital image!], K 000082212 [digital image!], M 0240742 [digital image!], P 00708602 [digital image!], P 00708603 [digital image!], US 01108197 [digital image!]).

Vine suffrutescent, twining, stems branched, glabrescent to sericeous, indumentum white, with yellow vesicular glands, but lacking bulbous-based trichomes. Stipules caducous. Leaves trifoliolate; petiole 1.5–3.1 cm long; leaf rachis 1.5–2 cm long; stipels lacking; leaflets 1.1–4.6 × 1.4–3.1 cm, ovate, rhombic to rounded, surface not bullate, acuminate to rounded at apex, obtuse to rounded at base, margin entire, pilose, with yellow vesicular glands on both surfaces. Inflorescences axillary, paniculate, 6.5–25 cm long, many-flowered, exceeding the length of the subtending leaf; bracts caducous; pedicel 1–2 mm long. Flowers 5–8 mm long excluding the pedicel; calyx 3–5 mm long, pilose to pubescent with yellow vesicular glands, but lacking bulbous-based trichomes, lobes triangular, not exceeding the corolla in length; standard petal ca. 7 × 4 mm, oblong, apiculate at apex, pilose to glabrescent, with yellow vesicular glands, but lacking bulbous-based trichomes, claw ca. 0.7 mm long, auricle ca. 0.5 mm long; wing petals ca. 4.8 × 1.5 mm, oblong, claw ca. 0.6 mm long, auricle ca. 0.5 mm long; keel petals ca. 5.7 × 2 mm, falcate, claw ca. 1.8 mm long; stamens ca. 6 mm long; ovary ca. 1.8 mm long, pilose, with yellow vesicular glands. Fruits 1.7–2.2 × 0.9–1.1 cm, reddish-brown to black, strongly constricted between the seeds, oblong to obovate, glabrescent, with yellow vesicular glands, bulbous-based trichomes absent. Seeds ca. 6 × 4 mm, suborbicular, bicolored, black and red, the red confined to hilar area.

Nomenclatural and taxonomic notes: — Grear (1978) cited two presumed isotypes deposited in BM and LE. Ståhl et al. (2016) designated the gathering C. J. W. Schiede & F. Deppe s.n. at HAL with barcode number 0098589 as the lectotype of R. erythrinoides , claiming that it is the only original material annotated by one of the authors (Chamisso). We follow this designation here.

Rhynchosia erythrinoides morphologically resembles R. melanocarpa and R. naineckensis in having reddish-brown to black fruit constricted between the seeds ( Figs. 4 D–E ; 6 I ) and bicolored black and red seeds with a restricted red area around the hilum. However, it differs from them by being leafless when flowering, by its suborbicular fruits ( Fig. 6 H ) and by the other characters listed in Table 1 .

Reproductive phenology: —Flowering from January to April and in June; fruiting from February to May and August to October.

Distribution and habitat: — Rhynchosia erythrinoides occurs in southern Mexico and in some Central American and Caribbean counties, including Costa Rica, Dominican Republic, Guatemala, Haiti, Honduras, Jamaica, Nicaragua and Panama. Grear (1978) mentioned that this species can also be found in Honduras, but we have not been able to confirm this. The species’ distribution in South America is restricted to Colombia, Ecuador, and French Guiana ( Fig. 7 ). Rhynchosia erythrinoides occurs in humid forests, rocky outcrops fields, in secondary vegetation and along roadsides.

Conservation status: —Least Concern (LC). Based on an EOO of 7,522,014 km 2 (GeoCAT, accessed in May 2022), R. erythrinoides is classified as LC following IUCN criteria ( IUCN 2022), due to its wide distribution.

Selected Specimens Examined:— COLOMBIA. El Valle : Cordoba Valle del Cauca, 17 February 1939 (fl./fr.), E. P. Killip & H. Garcia 33398 (BM 13715310) . COSTA RICA. Forested slopes above the lumber camp at the Rio Coton ( Las Alturas ), 15 January 1967 (fl.), W. Burger & G. Matta 4560 (BM 013715021) . CUBA. La Caridad , February 1889 (fl./fr.), H. F. A. Eggers 4710 (US 995699) . DOMINICAN REPUBLIC. Monte Plata: Pilancón, Bayaguana , 31 March 1973 (fl./fr.), A. H. Liogier 18866 ( NY) . ECUADOR. El Oro: Portovelo , October 1918 (fr.), J. N. Rose & G. Rose 23432 (US 2346848). FRENCH GUIANA. s.loc., 1967 (fr.), L. C. Richard s.n. (P) . GUATEMALA. Alta Verapaz: Pansamala , May 1887 (fr.), H. von Tuerckheim 1227 (US 2346235) . HAITI. Hispaniola: Vicinity of Bassin Bleu, Morne Haut Piton Ridge , April 1929 (fl./fr.), E. C. Leonard & G. M. Leonard 15087 (US 00874996) . JAMAICA. Bluefields Mountain, 7 March 1908 (fl./fr.), N. L. Britton 1962 ( NY); Chester Vale, 11 August 1895 (fr.), W. H. Harris 5875 ( NY); Monte Diablo, 2 April 1903 (fl.), W. H. Harris 8494 ( NY); Portland, Near Green Hill P.O., 30 March 1963 (fl.), G. R. Proctor 23411 ( NY); Saint Ann, Reynolds Mine area near Lydford P.O., 23 September 1954 (fr.), R. A. Howard 14100 ( NY) . MEXICO. Catemaco: Cumbre de Bastonal , 15 January 1974 (fl.), F. Ponce & R. Cedillo 11 (BM 13715022) . NICARAGUA. Chontales, June 1868 (fl.), R. Tate 104 (267) (BM 13715026) . PANAMA. Darien, Enseada del Guayabo, River Valley filled with landslide debris, 18 km SE Jaqué, 12 January 1983 (fl.), N. Garwood et al. 170 (BM 13715020) .

Figures

FIGURE 4. Detailed structures of Rhynchosia species. A–B. Portion of the stem and detail of fruit of R. burkartii. C. Stem of R. caaguazuensis showing the leaflets shape and inflorescences. D–E. Fruit of R. erythrinoides. F, G. Portion of the stem and detail of fruit of R. mantaroensis var. cuprinervia. (Illustrated by Klei Souza).

FIGURE 6. Rhynchosia species. A–C. R. diversifolia. D–G. R. edulis. H–I. R. erythrinoides. (A, B, E by T.C. Monteiro); (C by L.M.P.A. Bezerra); (D, F, G by D. S. Gissi) and (H, I by N. R. Marcial).

FIGURE 7. Geographical distribution of Rhynchosia diversifolia, R. edulis and R. erythrinoides in South America.