Macropsychanthus

Taxonomy

Macropsychanthus H.A.T. Harms ex K.M. Schumann & C.A.G. Lauterbach Fl. Deutsch. Schutzgeb. [C] Südsee 366. Nov 1900.

Subfamily: Faboideae.
Phylogenetic Number: 3.10.22.
Tribe: Phaseoleae.
Subtribe: Diocleinae.
Species Studied - Species in Genus: 2 studied; 4 in genus.

Description

Fruit: A legume; unilocular; 12.5–20 cm long (from literature); 4.3–5.5 cm wide (from literature); 1.6–2.5 cm thick (from literature); 2–9 times longer than wide (from literature); without orifice formed by curving of fruit or fruit segments; slightly curved; not plicate; not twisted; asymmetrical; falcate; with both sutures parallelly curved; not inflated; compressed (from literature); with beak (from literature); with solid beak the same color and texture as fruit (from literature); long tapered at apex, or rounded at apex (from literature); aligned with longitudinal axis of fruit; tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin constricted; margin constricted along both margins; margin without sulcus; margin plain; wing(s) absent. Epicarp dull; monochrome; brown; with surface texture uniform; assumed pubescent and indurate; with hairs erect; with 1 type of pubescence; sericeous; with pubescence golden; with pubescence uniformly distributed; with simple hairs; stiff; with hair bases plain; eglandular; without spines; not smooth; with recessed features; not veined; not tuberculate; grooved; not exfoliating; without cracks. Endocarp present; opaque; white (pieces sticking to seeds); without adhering pieces of testa; without wings. Seed(s) from literature 2–5. Aril present; dry; when dry narrow rim-aril; entire; covering less than 1/2 of seed; cream.

Seed: From literature 25–30 mm long; from literature 20–30 mm wide; from literature 10–18 mm thick; not overgrown; angular; symmetrical; D-shaped, or rectangular (nearly); compressed; with surface smooth; without visible radicle and cotyledon lobes; without hilar sinus; without umbo on seed faces, or with umbo on seed faces; with umbo on both faces of seed; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp, or partially adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; mottled; reddish brown; with brown overlay; glabrous; smooth, or not smooth; with elevated features; wrinkled, or tuberculate (from literature); osseous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 67–80 mm long; with straight outline (around 3/4 of seed); linear; marginal according to radicle tip; raised; not within corona, halo, or rim. Lens discernible; 2 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; recessed; same color as testa; brown; not within corona, halo, or rim. Endosperm absent. Cotyledons smooth; both outer faces convex; one thicker than the other (slightly); both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; partially concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; tan; inner face flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip straight; straight with embryonic axis; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

New Guinea, Philippines, and Micronesia.

Old World; Indonesia and the Philippines, Fiji, and Pacific (Philippines).

Generic Notes

Lackey (1981) noted "scarcely distinguishable from Dioclea" (10.18). The fruits and seeds of these genera are very similar. Partial fruit data from young fruits of Macropsychanthus lauterbachii Harms ssp. glabricalyx Verdcourt (isotype at US).

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.