Subfamily: Faboideae.
Phylogenetic Number: 3.10.40.
Tribe: Phaseoleae.
Subtribe: Glycininae.
Species Studied - Species in Genus: 2 studied; 2 in genus.
Fruit: A legume; unilocular; 1.5–3.5 cm long; 0.2–0.6 cm wide; 0.2–0.4 cm thick; 2–9 times longer than wide, or more than 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; not plicate; not twisted; asymmetrical, or symmetrical; slightly moniliform to linear (nearly); with both sutures parallelly curved, or both sutures nearly straight; not inflated; compressed; without beak, or with beak; straight; with solid beak the same color and texture as fruit (short); aligned with longitudinal axis of fruit; tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous to coriaceous (sub); seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin constricted; margin slightly constricted along both margins to constricted along both margins; 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; monochrome; brown; with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; sericeous to tomentose; with pubescence golden, or tan, or brown; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; not veined, or veined; transversely veined relative to fruit length; not tuberculate; sparsely papillose; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; chartaceous. Endocarp present; visible; dull; opaque; monochrome; tan to white; smooth; without adhering pieces of testa; septate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 2–10; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.5–1 mm long; of 1 length only; flattened; triangular. Aril present; dry; when dry rim-aril and tongue-aril; entire; white.
Seed: 4.6–5.6 mm long; 2.5–4 mm wide; 2.2–2.7 mm thick; not overgrown; not angular; asymmetrical; reniform to rectangular (nearly); 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; glossy, or dull; not modified by a bloom; colored; monochrome; brown; glabrous; not smooth, or smooth; with elevated features; powdery and not rubbing off; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; partially concealed; concealed by aril; without faboid split; larger than punctiform; 0.7–1 mm long; with curved outline; elliptic; marginal according to radicle tip; recessed; within halo; halo darker than testa. Lens discernible; 0.1–0.9 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; similar color as testa; darker than testa; within halo; halo color darker than testa. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire embryo, or restricted to region of embryo, or covering at least 1/2 of embryo, but not entire embryo; adnate to testa. Cotyledons not smooth; sulcate; 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; split over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; yellow, or tan; inner face flat; glabrous on inner face. Embryonic axis straight; perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip curved; deflexed and parallel to cotyledon length; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.