Subfamily: Faboideae.
Phylogenetic Number: 3.10.24.
Tribe: Phaseoleae.
Subtribe: Diocleinae.
Species Studied - Species in Genus: 7 studied; 12 in genus.
Fruit: A legume; unilocular; (4–)5–15 cm long; 0.6–1.4 cm wide; 0.2–0.3 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight, or curved (slightly); not plicate; not twisted; asymmetrical, or symmetrical; linear, or falcate; with both sutures parallelly curved; not inflated; compressed; with beak; with solid beak the same color and texture as fruit; tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit, or right-angled with longitudinal axis of fruit; tapered at base; oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain, or embellished; margin with thickened sutural areas; wing(s) absent; nonstipitate, or stipitate (rarely); with the stipe 5–7 mm long; 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; black; with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; puberulent, or velutinous, or sericeous; with pubescence golden, or white; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; not veined; not tuberculate; rugose, or scaly; not exfoliating; with cracks; cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; coriaceous. Endocarp present; visible; dull; opaque; monochrome, or mottled; brown; with brown overlay; smooth and floury-filamentous; without adhering pieces of testa; septate, or nonseptate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; exfoliating, or exfoliating in part; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 3–14; length transverse to fruit length (some round); neither overlapping nor touching; in 1 series. Funiculus 1–2 mm long; of 1 length only; flattened; straight. Aril present; dry; when dry rim-aril, or tongue-aril; entire; covering less than 1/2 of seed; tan.
Seed: (4.5–)8–9.6 mm long; 5.5–7.2 mm wide; 2.3–6 mm thick; not overgrown; not angular; symmetrical; elliptic, or ovate; terete, or 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; brown; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 1.5–2.8 mm long; with curved outline; oval; subapical to radicle tip, or marginal according to radicle tip; recessed; within rim and within halo; halo lighter than testa; rim color darker than testa. Lens discernible; 0.1–0.8(–2) mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; dissimilar color from testa; darker than testa; dark brown; not within corona, halo, or rim. Endosperm present; thin, or trace; not pluglike and not resembling tip of radicle; restricted to region of embryo, or covering at least 1/2 of embryo, but not entire embryo; adnate to testa. 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; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; tan; inner face flat; glabrous on inner face. Embryonic axis oblique to right angled; oblique to length of seed to perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip straight; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.