Rhynchosia

Taxonomy

Rhynchosia J. de Loureiro Nom. cons. Fl. Cochinch. 425, 460. Sep 1790.

Subfamily: Faboideae.
Phylogenetic Number: 3.10.80.
Tribe: Phaseoleae.
Subtribe: Cajaninae.
Species Studied - Species in Genus: 29 studied; 200 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 0.4–5.5 cm long; 0.3–1.2 cm wide; 0.2–0.5 cm thick; 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; straight to curved (slightly); not plicate; assumed not twisted; asymmetrical; falcate, or ovate, or harp-shaped, or irregular; with both sutures parallelly curved, or both sutures unequally curved; not inflated; compressed, or terete (Grear, 1978); with beak, or without beak (rarely); straight, or declined; with solid beak the same color and texture as fruit; tapered at apex, or short tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; long tapered at base, or tapered at base, or short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally visible to invisible; seed chambers with the raised seed chambers not torulose; 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; assumed apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome, or multicolored; mottled; brown, or green, or tan; with green overlay, or brown overlay (dark, rarely); mottling color combination constant; with mottling over seed chambers; with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence, or 2 types of pubescence; puberulent, or puberulent and pilose, or pilose (rarely); with pubescence golden, or white; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases swollen and plain, or swollen, or plain; glandular, or eglandular; with glandular hairs and dots; without spines; not smooth; with elevated features; veined; irregularly veined, or obliquely veined relative to fruit length (rarely); not tuberculate; glandular dotted, or pusticulate, or scurfy, or wrinkled (rarely); not exfoliating; with cracks, or without cracks; cracking transverse to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present, or absent; thin, or thick (rarely); 1-layered; without balsamic vesicles; with fibers, or without fibers (rarely); without reniform canals; fibrous throughout, or solid; chartaceous, or ligneous (rarely). Endocarp present; visible; dull, or glossy; opaque; monochrome, or mottled, or streaked (rarely); tan, or yellow, or white (rarely); with mottling over seed chambers; with brown overlay, or yellow overlay (rarely); cobwebby, or smooth, or smooth and floury-filamentous, or scurfy and smooth (rarely); without adhering pieces of testa; nonseptate; coriaceous, or chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; remaining fused to epicarp; without wings; entire. Seed(s) 2, or 1; length parallel with fruit length, or oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–1 mm long; of 1 length only; flattened; triangular, or curved. Aril present; hard fleshy, or dry; when fleshy caplike; entire; covering less than 1/2 of seed; when dry rim-aril, or 2-lipped rim-aril; entire; 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; cream to tan.

Seed: 2.5–9.5 mm long; 2–6.4 mm wide; 1.3–5.1 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; cordate, or elliptic, or ovate, or reniform, or bilobed, cicerlike; terete, or compressed, or flattened; 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; dull to glossy; not modified by a bloom; colored; monochrome, or bichrome, or mottled; with frequent mottles; black and red, or brown, or tan, or black, or yellow; with black overlay, or brown overlay, or gray overlay; glabrous; smooth, or not smooth; with elevated features, or recessed features; tuberculate; pitted with small separate pits; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines present, or absent; transverse. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible, or partially concealed, or fully concealed; concealed by aril; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 0.5–3.5 mm long; with curved outline; circular, or elliptic, or oval; apical according to radicle tip but marginal according to seed length; flush, or recessed; within rim, or within rim and within halo; halo darker than testa; rim color of testa, or lighter than testa, or darker than testa. Lens discernible; 0.5–2.1 mm long; with margins straight, or curved; linear; elliptic; not in groove of raphe; confluent with hilum; mounded, or flush; dissimilar color from testa; lighter than testa, or darker than testa; black, or brown, or purple; within rim, or within halo, or not within corona, halo, or rim; halo color darker than testa; rim color darker than testa. Endosperm present; trace; not pluglike and not resembling tip of radicle, or pluglike and resembling tip of radicle (rarely); 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, or with margin(s) recessed; with 1 margin recessed; recessed on side opposite from radicle; tan; inner face flat; glabrous on inner face. Embryonic axis deflexed, or 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; bulbose; lobe tip straight; 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.

Distribution

Pantropics.

New World and Old World; pantropical, pansubtropical, and pan warm temperate; United States to West Indies to Mexico to Central America to South America; Argentina, Peru, Brazil, and Ecuador; Mediterranean to Africa to Madagascar to Indian Ocean to India to Southwest Asia to China to Korea to Japan to Indochina to Indonesia and the Philippines to New Guinea to Australia to Pacific to Macaronesia.

Generic Notes

Grear (1978) monographed the New World species. Labat and Du Puy (1996) synonymized Baukea G.C.W. Vatke (3.10.76) with Rhynchosia. The specific epithet of the single Baukea species could not be transferred into Rhynchosia, so they created the new name R. baukea J.-N. Labat & D.J. Du Puy for it. Other faboid taxa with red and black seeds are Abrus prectorius (3.5.01), which are deadly poisonous, and some species of Ormosia (3.2.15).

Tribal Notes

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.