Dimorphandra

Taxonomy

Dimorphandra H.W. Schott In K. P. J. Sprengel, Syst. Veg. 4(2): 404. Jan-Jun 1827.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.1.43.
Tribe: Caesalpinieae.
Group: Dimorphandra.
Species Studied - Species in Genus: 15 studied; 25 in genus.

Description

Fruit: A legume; unilocular; 11–23 cm long; 2.5–9 cm wide; 0.5–1.6 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; linear, or falcate, or C-shaped, or harp-shaped (nearly); with both sutures parallelly curved, or both sutures unequally curved; not inflated; compressed; without beak; tapered at apex; aligned with longitudinal axis of fruit; short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous (subfleshy when fresh); seed chambers externally invisible, or visible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate; with the stipe 6–140 mm long; indehiscent, or with all layers dehiscing (elastically); splitting along suture(s). Dehiscence of valves along 1 suture, or both sutures; active, or passive; with valves twisting, or revolute. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; transversely veined relative to fruit length; not tuberculate; rugose; checking and exfoliating, or not exfoliating; with cracks; cracking longitudinal to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 1-layered, or 2-layered; without balsamic vesicles; without fibers; without reniform canals; solid; with spongy layer over solid layer; ligneous. Endocarp present; visible; dull; opaque; monochrome; white, or tan; smooth, or fibrous; without adhering pieces of testa; septate; exfoliating, or not exfoliating (tearing during dehiscence or spongy in indehiscent fruits); remaining fused to mesocarp and epicarp; entire. Seed(s) 7–21; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–3 mm long; of 1 length only; filiform; 1- plicate and straight, or triangular. Aril absent.

Seed: 14–22 mm long; 8–12 mm wide; 2–4 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; oblong, or irregular (one margin more arched than other); 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; reddish brown; glabrous; smooth, or not smooth; with elevated features, or recessed features; shagreen; obliquely striate; osseous. Pleurogram present (one arm smoothly curved and other irregular especially near hilar end); 90–100 %. Pseudopleurogram absent. Fracture lines present; reticulate (minute but throughout). Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by funicular remnant; without faboid split; larger than punctiform; 0.1–1.5 mm long; with angular outline; irregular (wedged shaped); subapical to radicle tip; flush; not within corona, halo, or rim. Lens not discernible. Endosperm present; thick; not pluglike and not resembling tip of radicle; adnate to embryo. 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 margins); with lobes; with lobes not touching; with the interface division terminating at base of radicle; without margins recessed; inner face flat; glabrous on inner face. Embryonic axis straight; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; centered between cotyledons. Plumule moderately developed; glabrous.

Distribution

Central and tropical South America (Mainly Amazonia).

New World; Central America and South America (mainly Amazonia); Peru, Brazil, Ecuador, and the Guianas.

Generic Notes

Sandwith (1932) discussed the parameters of Dimorphandra and Mora (1.42), using seed morphology as a key character. Silva (1981) named ]three new species.