Subfamily: Faboideae.
Phylogenetic Number: 3.10.59.
Tribe: Phaseoleae.
Subtribe: Phaseolinae.
Species Studied - Species in Genus: 1 studied; 1 in genus.
Fruit: A legume; unilocular; 7.5–8 cm long; 0.7 cm wide; more than 9 times longer than wide; with deciduous androecial sheath; with persistent calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; symmetrical; linear; not inflated; compressed; without beak; long tapered at apex; oblique with longitudinal axis of fruit; short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; assumed apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome; dark brown; with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; puberulent; with pubescence uniformly distributed; with simple hairs; with hair bases swollen; eglandular, or glandular; with glandular hairs; without spines; not smooth; with elevated features; not veined; not tuberculate; papillose; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; 1-layered; without balsamic vesicles; without fibers; without reniform canals; (sub-) ligneous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; septate; with septa eglandular; not exfoliating; without wings. Seed(s) 8–9; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.5 mm long; of 1 length only; thick; straight. Aril present; fleshy; when fleshy hippocrepiform rim-aril (bulbous at base); entire; covering less than 1/2 of seed; tan.
Seed: 5.2–6.4 mm long; 3.3–4 mm wide; 2.4–2.8 mm thick; not overgrown; not angular; asymmetrical; ovate; compressed; with surface smooth; without visible radicle and cotyledon lobes; without hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; mottled; with frequent mottles; brown; with brown overlay (darker); glabrous; not smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by aril; without faboid split; larger than punctiform; 3–4.2 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; recessed; within corona; corona color darker than testa. Lens discernible; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; similar color as testa; lighter than testa; brown; within corona; corona color lighter than testa. Endosperm apparently absent. Cotyledons smooth; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; partially concealing radicle; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; yellowish white; inner face flat; glabrous on inner face. Embryonic axis oblique; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; triangular; lobe tip straight; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed to well developed; glabrous.