Subfamily: Faboideae.
Phylogenetic Number: 3.10.81.
Tribe: Phaseoleae.
Subtribe: Cajaninae.
Species Studied - Species in Genus: 19 studied; 130 in genus.
Fruit: A legume; unilocular; 1–1.8 cm long; 0.7–1 cm wide; 0.4 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 persistent calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; slightly curved; not plicate; not twisted; asymmetrical; irregular, or reniform; with both sutures unequally curved; not inflated; compressed; with beak; straight, or declined; with solid beak the same color and texture as fruit; rounded at apex; oblique with longitudinal axis of fruit, or right-angled with longitudinal axis of fruit, or aligned with longitudinal axis of fruit; rounded at base, or short tapered at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally invisible, or visible; margin not constricted; margin without sulcus; margin plain; 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; reddish brown; with surface texture uniform; pubescent and indurate; with hairs erect; with 2 types of pubescence; sericeous, or tomentose, or villous, or pilose (sericeous to tomentose and villous or pilose); with pubescence golden; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain and swollen, or plain, or swollen; eglandular, or glandular; with glandular dots; without spines; not smooth, or smooth; with elevated features; not veined; not tuberculate; muricate; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; 1-layered; without balsamic vesicles; without reniform canals; solid; chartaceous. Endocarp present; visible; dull; opaque; monochrome, or mottled; tan, or brown; with mottling over seed chambers; with brown overlay, or gray overlay; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1, or 2; length transverse to fruit length, or oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.5–0.6 mm long; of 1 length only; flattened; straight, or triangular. Aril present; fleshy; when fleshy 2-lipped rim-aril; entire, or crenate; covering less than 1/2 of seed; without tongue (or flap) on lips of 2-lipped rim-aril, or with tongues (or flap) on lips of 2-lipped rim-aril; with 2 tongues or flaps, 1 on each lip of 2-lipped rim-aril.
Seed: 4.5–8.5 mm long; 2.7–5.5 mm wide; 2–3.5 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; oblong, or elliptic, or quadrangular (rarely); compressed to terete (nearly); 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; not modified by a bloom; colored; monochrome, or mottled; with frequent mottles; black, or brown (reddish); with brown overlay; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed to partially concealed; concealed by aril; with faboid split; larger than punctiform; 4–6.2 mm long; with straight outline; linear; apical according to radicle tip but marginal according to seed length; raised to flush; within rim; rim color darker than testa, or lighter than testa. Lens discernible; 0.5 mm long; with margins curved; punctiform; not in groove of raphe; confluent with hilum; mounded; similar color as testa; lighter than testa, or darker than testa; light brown; within rim; rim color darker than testa. Endosperm present, or absent; 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; white; inner face flat; glabrous on inner face. Embryonic axis oblique, or right angled; oblique to length of seed, or perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose to triangular; lobe tip straight to curved; deflexed and parallel to cotyledon length, or deflexed and parallel to cotyledon width, or oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed to well developed; glabrous.
Grear (1970) monographed the American species, and Jacques-Felix (1971) monographed the species of central and eastern Africa. Grear and Dengler (1976) studied the rim-aril of Eriosema glaziovii H.A.T. Harms and discussed its importance in distinguishing Eriosema from Rhynchosia. They also discussed the misinterpretation of Eriosema seeds as estrophiolate by Hutchinson (1964) and Bentham (1865).
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
