Leucostegane

Taxonomy

Leucostegane D. Prain Ann. Roy. Bot. Gard. (Calcutta) 9: 37. 1901.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.17.
Tribe: Detarieae.
Group: Hymenostegia.
Species Studied - Species in Genus: 2 studied; 2 in genus.

Description

Fruit: A legume; unilocular; 9–11 cm long; 3–4 cm wide; 0.6–0.8 cm thick; 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, or asymmetrical; dolabriform; with nearly 1 straight and 1 curved suture; widest near apex; not inflated; compressed; with beak; hooked, or straight; with solid beak the same color and texture as fruit; straight on ventral margin and dorsal margin tapered 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; ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin embellished; margin with wing(s); wing(s) present; wing(s) 1; wing(s) 0.1–2 mm wide; wing(s) sutural (ventral); wing(s) on 1 suture (ventral); substipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along 1 suture (ventral); active; with valves twisting. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; transversely veined relative to fruit length; not tuberculate; exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 2-layered; without balsamic vesicles; with fibers; without reniform canals; with fibers embedded in mealy tissue over solid layer; ligneous. Endocarp present; visible; dull; opaque; monochrome; brown; smooth (around seeds); without adhering pieces of testa; subseptate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 3; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–1 mm long; of 1 length only; flattened; straight. Aril absent.

Distribution

Malaya and Sarawak.

Old World; Indochina and Indonesia and the Philippines (Malaya and Sarawak).

Generic Notes

Only a fruit was available for examination.

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.