Pterocarpus

Taxonomy

Pterocarpus N. von Jacquin Nom. cons. Sel. Stirp. Amer. Hist. 283. Jan-Jul 1763.

Subfamily: Faboideae.
Phylogenetic Number: 3.4.17.
Tribe: Dalbergieae.
Group: Dalbergia.
Species Studied - Species in Genus: 11 studied; 20 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 2–13 cm long; 2–11 cm wide; 0.5–2.5 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, or with orifice formed by curving of fruit or fruit segments (somtimes almost coiled and forming an orifice); straight, or 0.5-coiled to 1-coiled; not plicate; not twisted; asymmetrical, or symmetrical; circular, or elliptic, or oblong; with both sutures nearly straight, or 1 straight and 1 curved suture, or both sutures parallelly curved; widest near middle or D-shaped; not inflated; compressed, or flattened; without beak; rounded at apex; right-angled with longitudinal axis of fruit (to about 180 degrees), or oblique with longitudinal axis of fruit, or aligned with longitudinal axis of fruit; short tapered at base, or rounded at base, or emarginate at base (to notched); aligned with longitudinal axis of fruit; with the apex and base uniform in texture; membranous, or coriaceous, or ligneous (especially seed chamber); seed chambers externally visible; seed chambers with the raised seed chambers torulose; margin constricted, or not constricted; margin slightly constricted along both margins; margin without sulcus; margin embellished; margin with wing(s); wing(s) present (and entire but in time eroding), or absent (P. officinalis N. von Jacquin); wing(s) 1; wing(s) 0.1–50 mm wide; wing(s) samaroid; wing(s) on 1 suture; stipitate, or substipitate; with the stipe 0.1–15 mm long; indehiscent. Replum invisible. Epicarp dull; monochrome; brown, or black; with surface texture uniform; glabrous, or glabrate; with hairs erect; with 1 type of pubescence; puberulent; with pubescence tan, or gray, or brown; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; with spines (over the seed chambers); with spines persistent; with spines same color as the rest of the fruit; not smooth; with elevated features; not veined, or veined; reticulately veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin (quite); surface uniformly veined, or not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; coriaceous to sub coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate, or septate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; with wing(s) extending into epicarp (and entire but in time eroding), or without wings (P. officinalis N. von Jacquin); entire. Seed(s) 1(–3); length oblique to fruit length, or transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; triangular; straight. Aril absent.

Seed: 7–14 mm long; 2–9 mm wide; 3–3.6 mm thick; not overgrown; not angular, or angular; asymmetrical; reniform, or D-shaped, or irregular; compressed; 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, or glossy; not modified by a bloom; colored; monochrome; brown (light to dark reddish), or tan; glabrous; smooth, or not smooth; with elevated features; wrinkled; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible, or visible; from hilum through lens to base of seed and terminating (near base); not bifurcating; darker than testa; brown (reddish); raised (slightly). Hilum present; visible, or partially concealed, or fully concealed; concealed by funicular remnant, or funiculus; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform, or punctiform; 0.3–1 mm long; with curved outline; circular, or elliptic; between cotyledon and radicle lobe; recessed; within rim; rim color darker than testa. Lens discernible; with margins curved; circular (nearly and with or without attenuate ends); not in groove of raphe; confluent with hilum (or nearly so); mounded; same color as testa; 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, or not smooth; 1–3 grooves on each face; both outer faces convex; both the same thickness; both more or less of equal length; not folded, or with only 1 folded; not 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; brown (reddish); 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; bulbose; lobe tip straight, or curved; deflexed and parallel to cotyledon width; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Pantropical.

New World and Old World; pantropical; West Indies to Mexico to Central America to South America; Argentina, Peru, Brazil, Ecuador, and the Guianas; Africa to Madagascar to Indian Ocean to India to Indochina to China to Indonesia and the Philippines to New Guinea to Pacific.

Old World crop.

Generic Notes

Rojo (1977) studied the Malesia-Pacific species and listed the 20 species worldwide that he recognized. His report focused on fruit characters and ecological factors relevant to species dispersal and speciation. The monograph by Breitenback (1973) of the excellent timber tree of South Africa, kiaat or Transvaal-teak (P. angolensis A.P. de Candolle) included an evaluation of fruits of selected species. The fruits of many species (about 80%) are winged, but some fruits have the wings reduced to a keel. The seed chamber may be smooth to spiny even within one species: P. indicus C.L. von Willdenow.

Tribal Notes

Tribe Dalbergieae

Lima (1989) analyzed the morphological characters of fruits, seeds and seedlings of the tribe and his characters and illustrations were used as a much appreciated source of accurate data. He also discussed the phylogeny of the tribe. Sousa and Sousa (1981) provided data to support their conclusion that the New World Lonchocarpinae be considered for tribal status: A segregate of the Dalbergieae. Hauman (1954) provided data on the Dalbergieae of Central Africa, and Lock (1989) listed the Dalbergieae for all of Africa. Thothathri (1986) reviewed the taxonomic status and systematic position of Asiatic Dalbergieae, and monographed tribe Dalbergieae for the Indian subcontinent (Thothathri, 1987). Morphological (Lima 1989) and molecular (Doyle et al. 1997) evidence has indicated that tribe Dalbergieae is polyphyletic.