Subfamily: Faboideae.
Phylogenetic Number: 3.28.01.
Tribe: Euchresteae.
Species Studied - Species in Genus: 2 studied; 4 in genus.
Fruit: A legume; unilocular; 1.2–2.2 cm long; 0.8–1 cm wide; 0.5–0.6 cm thick; length less than twice as long as width to 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; symmetrical; oblong; not inflated; compressed; without beak; rounded at apex; aligned with longitudinal axis of fruit; rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; fleshy (when fresh), or drupaceous, or leathery (when dry); seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate, or substipitate; with the stipe 3–12 mm long; indehiscent. Replum invisible. Epicarp dull, or glossy; monochrome; violet black; with surface texture uniform; glabrous; eglandular; without spines; smooth, or not smooth; with elevated features; not veined; not tuberculate; wrinkled; 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; spongy; coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan; cobwebby, or spongy; without adhering pieces of testa; nonseptate; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1; length parallel with fruit length. Funiculus straight. Aril absent.
Seed: 12–20 mm long; 6–8 mm wide; 3–4 mm thick; not overgrown; not angular; symmetrical; oblong; compressed; 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; partially adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; monochrome; tan; glabrous; smooth; chartaceous. Pleurogram absent. Fracture lines absent. Rim absent. Raphe visible; from hilum to near base of seed and terminating; not bifurcating; darker than testa; black; raised. Hilum present; visible; without faboid split; punctiform; subapical to radicle tip; flush; not within corona, halo, or rim. 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; completely concealing radicle; split over radicle; with lobes; with the interface division terminating at base of radicle; without margins recessed; red; inner face flat; glabrous on inner face. Embryonic axis right angled; perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; with 90 degree turn; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.
Ohashi (1978) reported on the taxonomy and distribution of E. japonica (J.D. Hooker) E.A. von Regal, and he concluded that E. trifoliolata E.D. Merrill is a synonym. Therefore, the number of species is four, not five. The testa is fragile and difficult to completely separate from the endocarp. The cotyledons are free of the testa and rattle when seeds are shaken. Apparently seeds germinate while still in the moist fruit. Our seed measurements are based on interior fruit measurements, because the testae were too fragile to measure.
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
