Subfamily: Faboideae.
Phylogenetic Number: 3.10.44.
Tribe: Phaseoleae.
Subtribe: Glycininae.
Species Studied - Species in Genus: 3 studied; 3 in genus.
Fruit: A legume; unilocular; 1.5–3.8 cm long; 0.5–1.1 cm wide; 0.2–0.8 cm thick; 2–9 times longer than wide, or length less than twice as long as width; with deciduous androecial sheath; with persistent corolla, or deciduous corolla; with various petals; with persistent calyx, or deciduous calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; slightly curved, or straight; not plicate; not twisted; asymmetrical, or symmetrical; oblong, or falcate; with 1 straight and 1 curved suture, or both sutures parallelly curved; widest near middle or D-shaped; not inflated; compressed; with beak, or without beak; straight; with solid beak the same color and texture as fruit; tapered at apex, or rounded at apex; aligned with longitudinal axis of fruit; tapered at base, or rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous to coriaceous; seed chambers externally visible to invisible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain, or embellished; margin with ridge(s); wing(s) absent; substipitate; with the stipe 2–4 mm long; with all layers dehiscing (above ground fruits), or indehiscent (below ground fruits); 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; tan, or brown; 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 (along sutural ridges (above ground fruits) or all over (below ground fruits)); with pubescence golden; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; smooth; veined; reticulately veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present (above ground fruits), or absent (below ground fruits); thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; chartaceous. Endocarp present (above ground fruits), or absent (below ground fruits); visible; dull; opaque; monochrome; tan; smooth, or cobwebby; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; remaining fused to epicarp; without wings; entire. Seed(s) 1–3; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.5–0.8 mm long; of 1 length only; flattened; triangular. Aril present, or absent; dry; when dry 2-lipped rim-aril; entire; with tongues (or flap) on lips of 2-lipped rim-aril; with 1 tongue or flap on 1 lip of 2-lipped rim-aril, or 2 tongues or flaps, 1 on each lip of 2-lipped rim-aril; cream.
Seed: 4–16 mm long; 4–11.3 mm wide; 1.5–7.4 mm thick; not overgrown, or overgrown, 1 seed filling entire fruit cavity; not angular; symmetrical; reniform, or ovate; compressed; with surface smooth, or ridged; without visible radicle and cotyledon lobes, or with visible radicle and cotyledon lobes; without external groove between 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; mottled; brown (or reddish brown); with brown overlay (dark); glabrous; smooth, or not smooth; with elevated features; wrinkled; coriaceous, or chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; partially concealed; concealed by aril; with faboid split, or without faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 0.5–2 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; recessed; within rim; rim color of testa, or darker than testa. Lens discernible; 0.5–1.5 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; similar color as testa; darker than testa; brown; not within corona, halo, or rim, or within rim; rim color darker than testa. Endosperm absent, or present; trace; not pluglike and not resembling tip of radicle; restricted to region of 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; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; tan, or white; 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; narrowly triangular; lobe tip curved; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed; glabrous.
North America, Africa, and Asia.
New World and Old World; United States, Canada, and Mexico; Russia, Africa, India, Indochina, China, and Korea.
Turner and Fearing (1964) monographed Amphicarpaea. Amphicarpaea bracteata has heteromorphic seeds with large underground, single-seeded fruits and aerial, 1–3-seeded fruits. The spelling of this genus, Amphicarpaea, has been conserved against 'Amphicarpa' (Greuter et al., 1994).
Authors: J.H. Kirkbride, Jr., C.R. Gunn, A.L. Weitzman, M.J. Dallwitz, K.R. Thiele
Content last updated April 2003
Released April 2024 on idtools.org
