Subfamily: Faboideae.
Phylogenetic Number: 3.10.03.
Tribe: Phaseoleae.
Subtribe: Erythrininae.
Species Studied - Species in Genus: 32 studied; 100 in genus.
Fruit: A legume (breaking between seed chambers into "articles"), or a nutlet; unilocular; 5–53 cm long; 2–5 cm wide; 0.5–2.5 cm thick; length less than twice as long as width, or 2–9 times longer than wide, or more than 9 times longer than wide; with 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; straight, or curved (slightly); not plicate; not twisted; asymmetrical, or symmetrical; linear, or moniliform, or oblong, or falcate, or elliptic, or fusiform, or ovate, or S-shaped, or irregular; with both sutures parallelly curved, or both sutures unequally curved; not inflated; flattened, or compressed; without beak, or with beak; declined; with papery fragile beak up to 1 cm long, or solid beak the same color and texture as fruit; long tapered at apex, or tapered at apex, or short tapered at apex, or rounded at apex, or truncate at apex, or cordate at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit, or right-angled with longitudinal axis of fruit; long tapered at base, or tapered at base, or truncate at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; leathery, or ligneous, or fragile, thinner than chartaceous, like Trifolium; seed chambers externally invisible, or visible; seed chambers with the raised seed chambers not torulose; margin not constricted, or constricted; margin constricted along both margins; margin without sulcus; margin embellished, or plain; margin with ridge(s), or thickened sutural areas, or wing(s); wing(s) present, or absent; wing(s) 4; wing(s) 3–15 mm wide; wing(s) valvular (2 longitudinal on each valve), or sutural (2 on each suture, sometimes undulate or dentate marginally); wing(s) on both valves; wing(s) on both sutures; nonstipitate, or substipitate, or stipitate; 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; black, or brown, or green; with surface texture uniform, or not uniform, with patches of different texture not restricted to the base and apex; pubescent and indurate and pubescent but soon deciduous, or pubescent and indurate, or pubescent but soon deciduous; with hairs erect, or appressed (occasionally); with 1 type of pubescence, or 2 types of pubescence; pilose, or velutinous; with pubescence golden (reddish), or red (brownish), or tan, or brown (to dark brown); with longitudinal bands of lighter and darker brown; with pubescence uniformly distributed; with simple hairs and complex hairs; with bristle-like hairs (irritating); stiff; with hair bases plain; straight (with minute barbs in literature); straight at apex; eglandular; without spines; not smooth; with elevated features, or recessed features; veined, or not veined; finely, reticulately veined; not tuberculate; ribbed (ribs up to 6 mm, sometimes "T"-shaped; sometimes revolute; oblique and running across entire fruit, or oblique and with a gap at center of fruit, or irregular; sometimes with undulate to dentate margins), or rugose, or wrinkled, or raised reticulate; rarely, transversely grooved; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 1-layered, or 2-layered; without balsamic vesicles; without fibers; without reniform canals; solid; with spongy layer over solid layer; coriaceous, or chartaceous. Endocarp present; visible; dull; opaque; monochrome; brown to dark brown, or white; smooth; without adhering pieces of testa; septate, or nonseptate; with septa thicker than paper, firm (up to 5mm thick); with septa eglandular; ligneous, or chartaceous; not exfoliating, or exfoliating in part; remaining fused to mesocarp and epicarp; with wing(s) extending into epicarp, or without wings. Seed(s) 1–16; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 1–30 mm long; of 1 length only; flattened, or thick; curved, or triangular. Aril present, or absent; fleshy, or dry; when fleshy annular; crenate to fimbriate; covering less than 1/2 of seed; when dry rim-aril; crenate to entire; covering less than 1/2 of seed; with tongues (or flap) on lips of 2-lipped rim-aril; with 1 tongue or flap on 1 lip of 2-lipped rim-aril; orange, or tan.
Seed: 10–37 mm long; 7–36 mm wide; 3–17.5 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; circular, or elliptic, or oblong, or ovate, or reniform; terete, or compressed; with surface smooth, or ridged (from literature); without visible radicle and cotyledon lobes; 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, or mottled, or streaked; with frequent mottles; with frequent streaks; black, or brown (dark, reddish, or orangish), or orange (pale), or tan, or white, or purple (blackish); with black overlay, or tan overlay, or orange overlay; glabrous; smooth, or not smooth (rarely); with elevated features; rugose, or rugose and wrinkled; osseous, or coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible, or partially concealed; concealed by funicular remnant; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 6–90 mm long; with straight outline (around 3/4 of seed circumference), or curved outline; elliptic; linear; marginal according to radicle tip; flush; not within corona, halo, or rim, or within rim; rim color of testa. Lens not discernible, or discernible; 1 mm long; with margins straight, or curved; linear; punctiform; not in groove of raphe; confluent with hilum, or adjacent to hilum; 1 mm from hilum; recessed; same color as testa; within rim, or not within corona, halo, or rim; rim color of 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; pale tan to brown; inner face flat; glabrous on inner face. Embryonic axis oblique; 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; triangular; lobe tip curved; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary to moderately developed; glabrous.
Mucuna has been monographed for various parts of Asia and the Pacific by Tateishi and Ohashi (1981) and Wilmot-Dear (1984, 1987, 1990, 1991, 1992). Some of the variation used for fruits is taken from those monographs. A single species, M. sloanei W. Fawcett & A.B. Rendle, has been reported for Argentina (Burkart, 1970). Mucuna seeds can be divided into two broad groups: 1) large, flat, discoid seeds with the hilum extending most of the circumference and without an aril and 2) compressed, oblong ovoid seeds with a very short hilum and a conspicuous rim-aril. The genus Stizolobium P. Browne was established for the species of the latter group. Traditionally it has been recognized at subgeneric rank as Mucuna subgen. Stizolobium (P. Browne) D. Prain (Verdcourt, 1970c). Aminah et al. (1974) studied the irritating hairs of Mucuna. Various species, from all over the world, are well known as ocean drift seeds with the common names true sea beans, burning beans, and horse eye beans (Gunn and Dennis 1976).
Tribe Phaseoleae
Bruneau et al. (1995) carried out cladistic analyses of tribe Phaseoleae using chloroplast DNA restriction site data. Their results indicated that the tribe is not monophyletic and that the tribal delimitations between Phaseoleae and Desmodieae (11) and between Phaseoleae and Millettieae (7) are problematic.
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
