Subfamily: Faboideae.
Phylogenetic Number: 3.10.56.
Tribe: Phaseoleae.
Subtribe: Phaseolinae.
Species Studied - Species in Genus: 1 studied; 2 in genus.
Fruit: A legume; unilocular; 7.7–10.5(–12) cm long; 0.5–1.1 cm wide; more than 9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent calyx, or deciduous 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, or terete (Du Puy et al., 2002); without beak, or with beak (Du Puy et al., 2002); straight; with solid beak the same color and texture as fruit; long tapered at apex; aligned with longitudinal axis of fruit; tapered at base to rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally invisible; margin not constricted, or constricted (Du Puy et al., 2002); margin slightly constricted along both margins; margin without sulcus; margin embellished; margin with slightly thickened sutural areas; wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome, or multicolored; mottled; brown to tan, or gray (pale); with brown overlay; mottling color combination constant; with mottling over seed chambers; with surface texture uniform; glabrous, or pubescent and indurate; with hairs erect; with 1 type of pubescence; puberulent; with pubescence golden; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; smooth, or not smooth; with elevated features; not veined; not tuberculate; wrinkled; not exfoliating; with cracks; cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 2-layered; with balsamic vesicles; without fibers; without reniform canals; with solid layer over spongy layer; coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan to white; fibrous and scurfy; without adhering pieces of testa; nonseptate, or septate (Otoptera madagascariensis R. Vig., Du Puy et al., 2002); with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; exfoliating in part; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) (2–)4–9; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.5–0.6 mm long; of 1 length only; flattened; triangular. Aril present; dry; when dry tiny, hippocrepiform rim-aril; entire; cream.
Seed: 7–10 mm long; 4–5.8 mm wide; 2.8–5.3 mm thick; not overgrown; not angular; symmetrical; elliptic to oblong; terete to 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; monochrome, or mottled; with frequent mottles; dark to pale brown or brown; with brown overlay (darker); glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible, or not visible; from hilum through lens and base of seed to point opposite hilum; not bifurcating; color of testa; raised. Hilum present; fully concealed; concealed by funicular remnant; without faboid split; larger than punctiform; 0.7–1 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; recessed; within rim; rim color darker than testa. Lens discernible, or not discernible; 0.8–1 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; recessed; similar color as testa; lighter than testa, or darker than testa; brown; within rim; rim color lighter than testa, or darker than testa. Endosperm absent. Cotyledons smooth, or not 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; not concealing radicle; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; yellow; 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 rudimentary; glabrous.