Sarcodum

Taxonomy

Sarcodum J. de Loureiro Fl. Cochinch. 425, 461. Sep 1790.

Subfamily: Faboideae.
Phylogenetic Number: 3.7.
Tribe: Millettieae.
Species Studied - Species in Genus: 2 studied; 2 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 6.2–9 cm long; 0.8–1.3 cm wide; 0.5–0.7 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; linear, or falcate; with both sutures parallelly curved; not inflated; compressed; with beak, or without beak; straight; with solid beak the same color and texture as fruit; short tapered at apex; aligned with longitudinal axis of fruit to oblique with longitudinal axis of fruit; tapered at base; aligned with longitudinal axis of fruit to oblique with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin constricted, or not constricted; margin slightly constricted along both margins; margin without sulcus; margin embellished; margin with ridge(s); wing(s) absent; substipitate; with the stipe ca. 5 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome; dark brown; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; not veined; not tuberculate; wrinkled; exfoliating, or exfoliating in part; without cracks, or with cracks; cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present, or absent; trace; surface uniformly veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; spongy; chartaceous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth and scurfy; without adhering pieces of testa; subseptate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; exfoliating, or exfoliating in part, or not exfoliating; separating from mesocarp; without wings; entire. Seed(s) 4–8; length parallel with fruit length, or oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 2.5–3 mm long; of 1 length only; flattened; triangular. Aril present; dry; when dry rim-aril; entire; brown.

Seed: 5–7.5 mm long; 3.5–5(–7) mm wide; 2.5–4.5 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; elliptic to reniform; terete; with surface smooth; with visible radicle and cotyledon lobes, or without visible radicle and cotyledon lobes; without external groove between radicle and cotyledon lobes; with shallow 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; smooth; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines present, or absent; irregular. Rim absent. Wing(s) absent. Raphe visible; from hilum through lens and terminating before base of seed; not bifurcating; color of testa, or lighter than testa; brown; raised. 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; 2–2.5 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; recessed; within rim; rim color of testa. Lens discernible; ca. 1 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 present; thin; not pluglike and not resembling tip of radicle; covering at least 1/2 of embryo, but not entire 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; tan to yellow; inner face flat; glabrous on inner face. Embryonic axis oblique; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip curved; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary, or well developed; glabrous.

Distribution

Indochina, Indonesia to the Philippines (1 sp.) and Solomon Islands (1 sp.).

Old World; Indochina, Indonesia and the Philippines, and Pacific (Solomon Islands).

Generic Notes

Geesink (1981) noted that the species from the Solomon Islands is the "genus unknown" in Verdcourt (1979, page 589). Adema (1999) described a new species for the genus, S. bicolor F. Adema, and presented a key to the two species in the genus.

Tribal Notes

Tribe Millettieae

Geesink (1981) treated this tribe, as others before him, under the tribal name Tephroseae, but we now know that its correct name is Millettieae. Recent tribal studies (Geesink, 1981, 1984; Polhill, 1994a, 1994b) have arranged the genera in alphabetical order without phylogenetic numbers. Geesink (1984) monographed tribe Millettieae, and presented descriptive notes about fruits and seeds and in situ fruit and seed drawings. However, we are not entirely following Geesink (1984) for generic parameters because he either questioned the status of many of his new genera or did not make the necessary species transfers. The few new genera which he clearly recognized are being accepted. Lavin et al. (1998) developed a preliminary infratribal classification of six informal groups using phytochrome nucleotides: Millettia group, Lonchocarpus group, Derris group, Tephrosia group, "primitive" group, and Phaseoleae group. Lavin (1987) transferred Sphinctospermum to Millettieae. Lavin and Doyle (1991) carried out cladistic analyses integrating morphological and chloroplast DNA data, and concluded that it is a member of Robineae where we have placed it (now 8.12).