Subfamily: Faboideae.
Phylogenetic Number: 3.10.68.
Tribe: Phaseoleae.
Subtribe: Phaseolinae.
Species Studied - Species in Genus: 3 studied; 4 in genus.
Fruit: A legume; unilocular; 4–10 cm long; 1.8–3.6 cm wide; 1.5–2.5 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; asymmetrical, or symmetrical; fusiform; with 1 straight and 1 curved suture; widest near middle or D-shaped; not inflated; compressed, or terete; with beak; straight, or declined; with solid beak the same color and texture as fruit; short tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; tapered at base, or rounded at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous, or coriaceous; seed chambers externally visible, or invisible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain, or embellished; margin with 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; multicolored; mottled; brown; with brown overlay; mottling color combination variable; with surface texture uniform; pubescent and indurate, or pubescent but soon deciduous; with hairs erect; with 1 type of pubescence; puberulent, or sericeous; with pubescence golden; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; smooth; not veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; chartaceous. Endocarp present; visible; dull; opaque; monochrome; white to tan; cobwebby, scurfy, smooth, and floury-filamentous; without adhering pieces of testa; subseptate; 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) 1–4; neither overlapping nor touching; in 1 series. Funiculus at least 4 mm long; of 1 length only; thick; anvil-shaped. Aril present, or absent; dry; when dry 2-lipped rim-aril; entire; without tongue (or flap) on lips of 2-lipped rim-aril; cream.
Seed: 13–20 mm long; 13–19 mm wide; 11–18 mm thick; not overgrown; not angular; symmetrical; circular, or elliptic (broadly); terete; 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; glossy to dull; not modified by a bloom; colored; monochrome; black to brown; glabrous; smooth, or not smooth; with elevated features; wrinkled; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines present, or absent; reticulate. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible, or partially concealed, or fully concealed; concealed by funicular remnant, or aril; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 13–25 mm long; with straight outline; linear; marginal according to radicle tip; flush; within rim; rim color of testa. Lens discernible; 2–4 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; same color as testa; brown; within rim; rim color of testa. Endosperm absent. Cotyledons smooth, or not smooth; wrinkled; both outer faces convex; both the same thickness; both more or less of equal length; with both folded, or not folded; sufficiently folded for inner face to touch itself; portions of inner folded face unequal; margin entire 180 degrees from base of radicle, or not entire 180 degrees from base of radicle; notched; similar at apex; partially concealing radicle; notched at radicle; without lobes; with the interface division terminating at base of radicle; with margin(s) recessed; with 1 margin recessed; recessed on same side as radicle; tan; 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; bulbose; lobe tip straight; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.