Nesphostylis

Taxonomy

Nesphostylis B. Verdcourt Kew Bull 24: 296. Mai 1970.

Subfamily: Faboideae.
Phylogenetic Number: 3.10.58.
Tribe: Phaseoleae.
Subtribe: Phaseolinae.
Species Studied - Species in Genus: 1 studied; 3 in genus.

Description

Fruit: A legume; unilocular; 10–15 cm long; 0.75–0.9 cm wide; more than 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; not plicate; not twisted; symmetrical; linear; not inflated; flattened; without beak; tapered at apex; aligned with longitudinal axis of fruit; short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; seed chambers externally invisible; margin not constricted; margin without sulcus; margin embellished; margin with thickened sutural areas; wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along assumed both sutures; assumed apical and down; assumed active; with valves assumed twisting. Replum invisible. Epicarp with surface texture uniform; pubescent and indurate; hairs erect; velutinous; pubescence gray to brown; not tuberculate. Aril present; fleshy; when fleshy hippocrepiform rim-aril (thick at connected end); entire; covering less than 1/2 of seed; without tongue (or flap) on lips of 2-lipped rim-aril; brown, or cream, or orange.

Seed: 5.5–8 mm long; 4–5 mm wide; 2.5–3.2 mm thick; not overgrown; not angular; symmetrical; ovate; 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; dark brown; glabrous; not smooth; with elevated features; wrinkled; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; partially concealed to fully concealed; concealed by funicular remnant and aril; without faboid split; larger than punctiform; 5–6.3 mm long; with straight outline; linear; marginal according to radicle tip; flush; not within corona, halo, or rim. Lens discernible; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; same color as testa; black to brown; not within corona, halo, or rim. 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; yellowish white; inner face flat; glabrous on inner face. Embryonic axis right angled; 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 width; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Africa (1 sp.), India (1 sp.), and Burma (1 sp.).

Old World; Africa, India, and Indochina.

Generic Notes

Potter and Doyle (1994) developed phylogenetic hypotheses for Nesphostylis, and altered the generic circumscription accordingly. Their species count and distribution were used. No fruit was dissected, and only one seed was studied. Some data taken from Verdcourt (1970a).

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.