Pterogyne

Taxonomy

Pterogyne E.L.R. Tulasne Ann. Sci. Nat. Bot. ser. 2. 20: 140. Sep 1843.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.1.37.
Tribe: Caesalpinieae.
Group: Pterogyne.
Species Studied - Species in Genus: 1 studied; 1 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 3.5–5 cm long; 1.1–1.5 cm wide; 0.2–0.3 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 to curved; not plicate; not twisted; symmetrical, or asymmetrical; samaroid; with both sutures unequally curved; not inflated; compressed; without beak; long tapered at apex; aligned with longitudinal axis of fruit; short tapered at base; oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally visible; margin constricted; margin constricted along both margins (?); margin without sulcus; margin embellished; margin with wing(s); wing(s) present; wing(s) 3.5 mm wide; wing(s) samaroid; wing(s) apical; substipitate (?); indehiscent. Replum invisible. Epicarp glossy; monochrome; reddish to yellowish brown; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features, or recessed features; veined; reticulately veined; not tuberculate; pitted; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 2-layered; without balsamic vesicles; with fibers; without reniform canals; with fibers over spongy tissue (thin); coriaceous. Endocarp present; visible; dull; opaque; monochrome; brown; without adhering pieces of testa; nonseptate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 1; length parallel with fruit length. Funiculus 0.1–1.7 mm long; of 1 length only; filiform; straight and curved. Aril absent.

Seed: 12–13 mm long; 6–7 mm wide; 2–2.5 mm thick; not overgrown; not angular; symmetrical; ovate; 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; glossy; not modified by a bloom; colored; monochrome; dullish brown; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines present; reticulate. Rim absent. Wing(s) absent. Raphe visible (well-defined from hilum to base). Hilum present; visible; without faboid split; punctiform; subapical to radicle tip; flush; not within corona, halo, or rim. Lens discernible; 0.4 mm long; with margins curved; elliptic; not in groove of raphe; mounded; similar color as testa; darker than testa (halo); not within corona, halo, or rim. Endosperm present; thick; not pluglike and not resembling tip of radicle; 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 (lower half concealed); with lobes; with lobes touching (auriculate); without basal groin formed by lobes; with the interface division terminating at base of radicle; without margins recessed; inner face flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; centered between cotyledons. Plumule rudimentary; glabrous.

Distribution

Brazil, Paraguay, and northern Argentina.

New World; South America (Brazil, Paraguay, and northern Argentina); Argentina and Brazil.

Generic Notes

Fruits of Pterogyne appear identical to fruits of Pterolobium (1.27), except for the location of the style (or stylar remnant). In Pterogyne the style is at the tip of the seed chamber (not the wing), whereas in Pterolobium it is at the apex of the wing (not the seed chamber). The seed chamber is apical and the wing dorsal in the similar samaroid fruits of Neoapaloxylon (4.29) and Brandzeia (4.28), both in the Detarieae. Like Poeppigia (1.36), there is no pleurogram on the seeds of Pterogyne, though there clearly are two parts to the face of a seed: Marginal, which is glossy, slightly lighter colored, and without fracture lines, and facial, which is duller, darker colored, and with fracture lines. Polhill and Vidal (1981) also noted the presence of "the beak with a hilar cavity and a second cavity with a plug." There is a hilar cavity, and the plugged cavity may refer to the presence of a well-defined lens. Watson and Dallwitz (1983) described the seeds as "non-endospermic".