Cynometra

Taxonomy

Cynometra C. Linnaeus Sp. Pl. 382. 1 Mai 1753.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.01.
Tribe: Detarieae.
Group: Cynometra.
Species Studied - Species in Genus: 28 studied; ca. 70 in genus.

Description

Fruit: A legume; unilocular; 0.6–13 cm long; 0.3–5 cm wide; 0.6–2 cm thick; length less than twice as long as width; 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, or asymmetrical; vertically grooved ovate, or oblong, or C-shaped, or irregular (nearly), or reniform (with one side being straight); with both sutures unequally curved, or both sutures parallelly curved, or 1 straight and 1 curved suture; widest near middle or D-shaped; not inflated; flattened to terete (valves terete or subterete); without beak; long tapered at apex to tapered at apex; aligned with longitudinal axis of fruit to right-angled with longitudinal axis of fruit; rounded at base; oblique with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally invisible; margin not constricted; margin often with sulcus, or without sulcus; margin plain; wing(s) absent; stipitate to nonstipitate; with the stipe 0.1–10 mm long; with all layers dehiscing, or indehiscent; splitting along suture(s). Dehiscence of valves along both sutures (?); active; with valves tearing 1 or more times concentrically in terete forms, or in flattened forms dehiscing elastically and separately enrolling, or revolute (?). Replum invisible. Epicarp dull; monochrome; light reddish brown, or tan; with surface texture uniform; densely pubescent and indurate, or glabrous; with hairs erect; with simple hairs (gray velvety); eglandular; without spines; smooth, or not smooth; with elevated features; not veined; not tuberculate; reticulately rugose, or tuberculate, or scaly; checking and exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 1-layered (?); without balsamic vesicles; without fibers; without reniform canals; spongy; ligneous (tearing concentrically in C. hostmanniana). Endocarp present; visible; dull; opaque; monochrome; brown; without adhering pieces of testa; septate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 1–2(–4); length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–0.4 mm long; of 1 length only; thick; straight. Aril absent.

Seed: 9–35 mm long; 0.7–28 mm wide; 0.3–20 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; circular to oblong, or D-shaped to irregular (with 1 straight side); compressed; 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; not modified by a bloom; colored; monochrome; brown; glabrous; not smooth; with elevated features, or recessed features; seldom glandular to pubescent, often remnants of endocarp appearing scurfy or shagreen, or rugose; seldom pitted with small separate pits; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible (from hilum to base). Hilum present; visible; without faboid split; punctiform; apical at apex of radicle tip, or subapical to radicle tip (often at right angles to seed length); flush; not within corona, halo, or rim. Lens not discernible. 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, or partially concealing radicle; notched at radicle, or split over radicle; with the interface division terminating at base of radicle; without margins recessed; inner face flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed, or perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; centered between cotyledons. Plumule rudimentary to well developed; glabrous.

Distribution

New World, Africa, Madagascar, Indomalaysia-Pacific region.

New World and Old World; Mexico, West Indies, Central America, and South America; Argentina, Peru, Brazil, Ecuador, and the Guianas; Africa, Madagascar, India, Indochina, Indonesia and the Philippines, Australia, and Fiji.

Generic Notes

Dwyer (1958) monographed the New World species of Cynometra, and a student of M.F. da Silva, is studying this genus.

Tribal Notes

Tribe Detarieae

Bruneau et al. (2000) carried out extensive phylogenetic analyses of tribes Amherstieae and Detarieae. They concluded that they form a single monophyletic group. Therefore, they supported Polhill's (1995a, 1995b) decision to unite the two tribes.