Subfamily: Faboideae.
Phylogenetic Number: 3.10.46.
Tribe: Phaseoleae.
Subtribe: Glycininae.
Species Studied - Species in Genus: 4 studied; 5 in genus.
Fruit: A legume; unilocular; 6–25.5 cm long; 0.8–2.8 cm wide; 0.3–0.6 cm thick; 2–9 times longer than wide, or more than 9 times longer than wide; with persistent androecial sheath, or 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; slightly curved; not plicate; not twisted; asymmetrical, or symmetrical; linear; with both sutures parallelly curved; not inflated; compressed to terete; without beak; tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; long tapered at base, or tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain, or embellished; margin with flange(s) (narrow), or 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; with black overlay, or brown overlay, or gray overlay; mottling color combination variable; with surface texture uniform; pubescent and indurate, or pubescent but soon deciduous; with hairs erect, or appressed; with 1 type of pubescence; tomentose, or sericeous (and appressed); with pubescence golden; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; smooth, or not smooth; with recessed features; not veined; not tuberculate; grooved; not exfoliating; with cracks, or without 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 reniform canals; solid; coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth and scurfy; without adhering pieces of testa; septate; with septa thicker than paper, firm; with septa eglandular; chartaceous; exfoliating in part; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 4–12(–18); length transverse to fruit length, or parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 1–2 mm long; of 1 length only; flattened; triangular. Aril present; dry; when dry tongue-aril, or 2-lipped rim-aril; entire; covering less than 1/2 of seed; cream.
Seed: 9.5–15.5 mm long; 9–14.5 mm wide; 4.5–6.5 mm thick; not overgrown; angular, or not angular; symmetrical, or asymmetrical; D-shaped, or quadrangular, or rectangular, or reniform; 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 to reddish brown, or green (olive), or red (brownish), or black; glabrous; smooth, or not smooth; with recessed features; pitted with small separate pits; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent, or present; transverse. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; partially concealed; concealed by aril; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 3.5–4 mm long; with curved outline; elliptic; apical at apex of radicle tip; recessed; within rim; rim color of testa. Lens discernible; 2.3–2.5 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; recessed; dissimilar color from testa; black; within rim; rim color of testa, or darker than testa. Endosperm 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; white to tan; inner face flat; glabrous on inner face. Embryonic axis straight, or oblique; parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip straight, or curved (slightly); straight with embryonic axis; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary to moderately developed; glabrous.