Hymenaea

Taxonomy

Hymenaea C. Linnaeus Sp. Pl. 1192. 1 Mai 1753.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.24.
Tribe: Detarieae.
Group: Hymenaea.
Species Studied - Species in Genus: 14 studied; 15 in genus.

Description

Fruit: A legume; unilocular; 2.5–17 cm long; 1.5–9 cm wide; 1.2–4 cm thick; length less than twice as long as width to 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; not plicate; not twisted; symmetrical, or asymmetrical; lanceolate, or oblong, or obovate; with nearly 1 straight and 1 curved suture; widest near apex (stated as scimitar-shaped); not inflated; compressed to subtriangular; without beak; tapered at apex; aligned with longitudinal axis of fruit; rounded at base; aligned with longitudinal axis of fruit to right angled with longitudinal axis of fruit; with the apex and base uniform in texture; drupaceous, or ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain, or embellished; margin with thickened sutural areas; wing(s) absent; stipitate to nonstipitate; with the stipe 1–12 mm long; indehiscent. Replum invisible. Epicarp dull to glossy; monochrome; brown; with surface texture uniform; glabrous; eglandular; without spines; usually smooth, or not smooth; with elevated features; not veined; not tuberculate; dotted, or verrucose-rugose, or lenticular (with the lenticels numerous, minute and creamy white to reddish), or warty (Hymenaea verrucosa Gaertn.); not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid, or mealy (containing resinous globules); ligneous. Endocarp present; visible; glossy (?); opaque; monochrome; yellowish brown; floury-filamentous, or pithy to vitriol (becoming so when dry); without adhering pieces of testa; nonseptate; exfoliating, or not exfoliating (?, either adnate to testa and falling with seeds, remaining attached to mesocarp leaving the testa fully exposed); remaining fused to mesocarp and epicarp; entire. Seed(s) 1–12; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–3 mm long; of 1 length only; thick; straight. Aril absent.

Seed: 12- 13–35 mm long; 9–20 mm wide; 8–15 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; elliptic to ovate, or irregular; 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 to dull; not modified by a bloom; colored; monochrome; brown; glabrous; smooth; osseous. Pleurogram absent. Pseudopleurogram absent. Fracture lines present, or absent; concentric, or reticulate. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible, or fully concealed; without faboid split; punctiform; apical at apex of radicle tip; flush (in base of depression); not within corona, halo, or rim. Lens discernible; 0.1–15 mm long; with margins curved; elliptic to circular; not in groove of raphe; mounded; similar color as testa; lighter than testa (bright reddish or yellowish brown); not within corona, halo, or rim. Endosperm absent. Cotyledons not smooth; 1–3 grooves on each face (outter surface only); 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; completely concealing radicle; split over radicle; with the interface division terminating at base of radicle; with margin(s) 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

Mexico, Central and tropical South America, and one species endemic to the east coast of Africa, Madagascar, Mascarenes.

New World and Old World; Mexico, West Indies, Central America, and South America (tropical); Peru, Brazil, Ecuador, and the Guianas; east coast Africa, Madagascar, and Indian Ocean (Mascarenes).

Generic Notes

Lee and Langenheim (1975) monographed the genus and noted that the pulpy endocarp is sweet, odoriferous, and edible. The testa intrudes into the cotyledons producing shallow, longitudinal, and vertical furrows. Janzen (1983) discussed the ecology of H. courbaril L. Its fruits have been described as 'anachronistic' because they supposedly evolved for dispersal by Pleistocene megafauna that are now extinct (Barlow 2000).

Tribal Notes

Tribe Detarieae

Bruneau et al. (2000) carried out extensive phylogenetic analyses of tribes Amherstieae and Detarieae. They concluded that they form a single monophyletic group. Therefore, they supported Polhill's (1995a, 1995b) decision to unite the two tribes.