Platypodium

Taxonomy

Platypodium J.R.T. Vogel Linnaea 11: 420. Apr-Jul 1837.

Subfamily: Faboideae.
Phylogenetic Number: 3.4.14.
Tribe: Dalbergieae.
Group: Dalbergia.
Species Studied - Species in Genus: 1 studied; 1 in genus, or 2 in genus.

Description

Fruit: A legume; unilocular; 6.5–13.5 cm long; 1.9–4 cm wide; 0.7–1.2 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, or curved (slightly); not plicate; not twisted; asymmetrical; samaroid; with both sutures unequally curved; not inflated; flattened (wing), or compressed (seed chamber); without beak; short tapered at apex; oblique with longitudinal axis of fruit (slightly); long tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous (seed chamber); seed chambers externally visible; seed chambers with the raised seed chambers torulose; margin not constricted; margin without sulcus; margin embellished; margin with wing(s); wing(s) present; wing(s) 1; wing(s) samaroid; wing(s) basal; wing(s) on 1 suture; stipitate; with the stipe 5–15 mm long; indehiscent. Replum invisible. Epicarp dull; monochrome (though somewhat reddish-brown over seed chamber); brown (reddish over seed chamber and tan winged or with an overall reddish-brown cast), or tan; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined and longitudinally veined relative to fruit length; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; ligneous (sub). Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; with wing(s) extending into epicarp; entire. Seed(s) 1(–2); length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 2 mm long; of 1 length only; thick; straight (nearly). Aril absent.

Seed: 17 mm long; 10 mm wide; 3 mm thick; not overgrown; not angular; asymmetrical; reniform; compressed; with surface smooth; 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; brown (reddish); glabrous; not smooth; with elevated features; wrinkled; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible; from hilum to near base of seed and terminating; not bifurcating; darker than testa (slightly); brown (reddish); recessed (slightly). Hilum present; fully concealed; concealed by funicular remnant; without faboid split; punctiform; between cotyledon and radicle lobe; recessed; not within corona, halo, or rim. Lens not discernible. Endosperm absent. 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; not 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 deflexed; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip straight; deflexed and parallel to cotyledon width; centered between cotyledons; less than 1/2 length of cotyledons. Plumule well developed; glabrous.

Distribution

Panama, Guatemala, Colombia, Venezuela, Bolivia, Brazil, and Paraguay.

New World; Central America (Guatemala, Panama), or South America (Venezuela, Bolivia, Brazil and Paraguay); Brazil.

Generic Notes

Polhill (1981d) noted that this genus has "probably only one or two species," but recently annotated herbarium sheets indicate that there may be only one species.

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.