Smithia

Taxonomy

Smithia W. Aiton Nom. cons. Hortus Kew. 3: 496. 7 Aug-1 Oct 1789.

Subfamily: Faboideae.
Phylogenetic Number: 3.14.12.
Tribe: Aeschynomeneae.
Subtribe: Aeschynomeninae.
Species Studied - Species in Genus: 12 studied; ca. 30 in genus.

Description

Fruit: A lomentloment:
usually dry fruit derived from a single carpel that breaks transversely into one-seeded fruit segments
(or a lomentloment:
usually dry fruit derived from a single carpel that breaks transversely into one-seeded fruit segments
segment); 1–1.5 cm long (estimated); 0.15–0.3 cm wide; 0.2–0.22 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent calyx; with calyx longer than fruit; without orifice formed by curving of fruit or fruit segments; contorted; plicate; not twisted; asymmetrical; moniliform; with both sutures parallelly curved; not inflated; compressed; without beak; rounded at apex; aligned with longitudinal axis of fruit (probably); rounded at base; aligned with longitudinal axis of fruit (probably); with the apex and base uniform in texture; chartaceous; seed chambers externally visible; margin constricted; margin constricted along both margins; margin without sulcus; margin plain; wing(s) absent; substipitate; indehiscent. Replum invisible. Lomentloment:
usually dry fruit derived from a single carpel that breaks transversely into one-seeded fruit segments
indehiscent; segments (articles) inconspicuous; segments (articles) 2–3 mm long; segments (articles) widest across seed area; segments (articles) with all essentially similar in shape; segments (articles) circular. Epicarp dull; monochrome; with surface texture uniform; glabrous; without spines; smooth, or not smooth; with elevated features; veined, or not veined; reticulately veined; tuberculate, or not tuberculate; with solid tubercles on each valve; tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp absent. Endocarp present; visible; dull; opaque; monochrome; tan; without adhering pieces of testa; septate; with septa thicker than paper, firm; with septa eglandular; chartaceous; not exfoliating; remaining fused to epicarp; without wings; entire. Seed(s) 4–7; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only. Aril absent.

Seed: 1.5–1.8 mm long; 1.3 mm wide; 0.5 mm thick; not overgrown; not angular; asymmetrical; reniform; compressed; with visible radicle and cotyledon lobes; without external groove between 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; reddish brown; glabrous; smooth; coriaceous. 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; punctiform; between cotyledon and radicle lobe; flush; not within corona, halo, or rim, or within halo; halo darker than testa. Lens discernible; with margins curved; elliptic; not in groove of raphe; adjacent to hilum; mounded; dissimilar color from testa; darker than testa; black; 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; not folded; margin entire 180 degrees from base of radicle; differing at apex (1 concealed by overarching radicle and other auriculate and concealing radicle); partially concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; yellow; inner face flat; glabrous on inner face. Embryonic axis deflexed; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip straight; deflexed and parallel to cotyledon length, or deflexed and parallel to cotyledon width; not centered between cotyledons (radicle outside 1 cotyledon and inside other, therefore junctions for each cotyledon different); 1/2 to nearly length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Old World tropics, Mainly Asia, Madagascar, and Africa.

Old World; tropical Africa to Madagascar to India to Indochina to China to Japan to Australia to Indonesia and the Philippines to Southwest Asia.

Generic Notes

Dewit and Duvigneaud (1954a and b) evaluated the species of Smithia in the Congo. The testa is thin, and the cotyledons are soft, making it difficult to remove the embryo. This is unlike most faboid legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
seeds, whose embryos are easy to remove from the testa.

Tribal Notes

Tribe Aeschynomeneae

Rudd (1981a) recognized four subtribes of Aeschynomeneae: Ormocarpinae V.E. Rudd (genera 3.14.01–3.14.08), Aeschynomeninae (genera 3.14.09–3.14.16), Discolobinae (A.E. Burkart) V.E. Rudd (genus 3.14.17: Discolobium), Poiretiinae (A.E. Burkart) V.E. Rudd (genera 3.14.18–3.14.21), and Stylosanthinae (G. Bentham) V.E. Rudd (genera 3.14.22–13.4.26). Tribal and subtribal placement of Diphysa is based on Lavin (1987; Polhill, 1994a, 1994b), and not on Polhill and Sousa (1981), who placed Diphysa in Robinieae. Bailey et al. (1997), using the chloroplast rpl2 intron and ORF184, suggested that Brya (11.01), Cranocarpus (11.02), Phylacium (11.22), and Neocollettia (11.26) are not members of Desmodieae (11) and that they probably belong in Aeschynomeneae.