Subfamily: Faboideae.
Phylogenetic Number: 3.3.01.
Tribe: Dipteryxeae.
Species Studied - Species in Genus: 9 studied; ca. 10 in genus.
Fruit: A nutlet, or a legume; unilocular; 4.2–6.3 cm long; 2.4–3.5 cm wide; 1.6–3 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; straight; not plicate; not twisted; symmetrical; circular to elliptic to ovate; not inflated; compressed; without beak; short tapered at apex to rounded at apex; aligned with longitudinal axis of fruit; rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; drupaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; stipitate; with the stipe 15 mm long; indehiscent. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; glabrous (when dry), or pubescent but soon deciduous (when fresh); with hairs erect; with pubescence uniformly distributed; with simple hairs; eglandular; without spines; not smooth; with elevated features; not veined; not tuberculate; exfoliating; with cracks; cracking irregular; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 1-layered, or 2-layered; with balsamic vesicles; with fibers; without reniform canals; firm-walled open empty cells (with balsamic vesicle); with fibers over solid layer; ligneous. Endocarp present; visible; dull; opaque; monochrome; red (dish); fibrous (white fibers over reddish surface in D. trifoliolata W.A. Ducke), or smooth; without adhering pieces of testa; nonseptate; coriaceous; exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 1; length parallel with fruit length. Funiculus 0.5–1 mm long; thick; straight. Aril absent.
Seed: 23–50 mm long; 13–15 mm wide; 4–8 mm thick; not overgrown; not angular; symmetrical; elliptic, or oblong, or ovate and linear; compressed; with surface grooved; reticulate; 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; dull; not modified by a bloom; colored; monochrome; black; glabrous; not smooth; with elevated features; wrinkled (reticulately); coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Raphe not visible. Hilum present; fully concealed; concealed by funicular remnant; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 5 mm long; with curved outline; elliptic; subapical to radicle tip, or marginal according to radicle tip; flush; not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons not smooth; wrinkled; 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 (by radicle); notched at radicle, or split over radicle; without lobes, or with lobes; with the interface division terminating at base of radicle; without margins recessed; yellow, or red (dish); 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; linear; straight with embryonic axis; centered between cotyledons; less than 1/2 length of cotyledons. Plumule well developed; glabrous.