Pongamiopsis

Taxonomy

Pongamiopsis R. Viguier Notul. Syst. (Paris) 14: 74. Feb 1950.

Subfamily: Faboideae.
Phylogenetic Number: 3.7.
Tribe: Millettieae.
Species Studied - Species in Genus: 2 studied; 3 in genus (Du Puy et al., 2002).

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 1.7–7 cm long; 1.2–3.5 cm wide; 0.5–3.5 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; asymmetrical; obliquely obovate, or irregularly fusiform; with both sutures unequally curved; inflated; terete; with beak; straight; with solid beak the same color and texture as fruit; short tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; rounded at base, or short tapered at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous, or ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin embellished, or plain; margin with ridge(s); wing(s) absent; nonstipitate; indehiscent, or with all layers dehiscing (eventually); splitting along suture(s). Dehiscence of valves along both sutures; passive. Replum invisible. Epicarp dull; monochrome; tan; with surface texture uniform; pubescent and indurate; with hairs erect, or appressed; with 1 type of pubescence; puberulent, or sericeous; with pubescence white; with pubescence uniformly distributed; with simple hairs; stiff; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick, or thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; ligneous, or coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–5; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus ca. 2 mm long; of 1 length only; thick; straight. Aril present; dry; when dry very thin rim-aril; entire; covering less than 1/2 of seed; without tongue (or flap) on lips of 2-lipped rim-aril; tan.

Seed: 10–15 mm long; 6–15 mm wide; 6–15 mm thick; not overgrown; not angular; asymmetrical; irregular, or elliptic, or circular (sub); 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, or gray (dark); glabrous; not smooth; with elevated features; transversely ridged; chartaceous. 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 lighter colored than the rest of the hilum and therefore conspicuous; larger than punctiform; ca. 2.5 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; raised; within rim; rim color of testa. Lens discernible; 0.7–1 mm long; with margins curved; ovate; not in groove of raphe; adjacent to hilum; 1 mm from hilum; mounded; same color as testa; dark brown; not within corona, halo, or rim. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to testa. Cotyledons smooth; both outer faces convex; both the same thickness; both more or less of equal length; with both folded (one more than the other); sufficiently folded for inner face to touch itself; portions of inner folded face unequal; 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; yellow; inner face wavy; 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; linear; lobe tip straight; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Madagascar.

Old World; Madagascar.

Generic Notes

Labat and Du Puy (1995) and Du Puy et al. (2002) maintained this genus separate from Millettia (Millettieae). Their species count and distribution were used. Little material was available for study. Only one seed was studied internally, and the fruit of only one species was studied internally.

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).