Microphyllidious trees to 30 m, resembling E. schomburgkii in indumentum and in inflorescence architecture, but the lfts somewhat wider, the fls nearly twice as large, and the ovary less pubescent and less obliquely yet strongly truncate; perulate buds not seen, but the growth obviously seasonal as in E. schomburgkii. Stipules on new growth thick-coriaceous, inequilaterally triangular-lanceolate or lanceolate 4.0-4.75 x 2.0-2.25 mm, quickly deciduous from a transverse scar. Lf-formula xvi-xxiii/35- 49; lf-stks 6.5-14 cm; petiole 9-20 mm, tapering from an enlarged but scarcely differentiated pulvinus, at middle 0.8-1.8 mm diam; petiolar nectary directly adjacent to pulvinus, at midpetiole, or close to first pinna-pair, sessile, cupular thick-rimmed 1.0-1.4 mm diam, similar but smaller nectaries between ultimate 3-5 pinna-pairs; interpinnal segments 3-6 mm; pinnae a little decrescent at both ends of lf-stk, the rachis of longer ones (2.6-)3.5-5.7 cm; interfoliolar segments 0.5-0.85(-l) mm; lfts attached on the ventral side of the lf-stk, adjacent to a centric rib, appearing to the naked eye sessile against rachis, the darkened wrinkled lft-pulvinules ±0.3-0.35 mm; lfts decrescent at each end of pinna, linear to linear-elliptic from an inequilaterally truncate base, at apex broadly acuminate, straight, plane, commonly ciliolate, the longer ones 5-6 x 0.7-1.2 mm, venation reduced to a forwardly displaced midrib dividing blade 1:2-3. Peduncles 1—2(—3) per node, 1.2-3.6 cm; capitula 32- 38-fld, the clavate or globose receptacle ±3.0-5.25 mm; bracts persistent into anthesis, that of peripheral fls linear-spatulate to oblanceolate ±1 mm, hyaline-margined, pubescent at apex, that of terminal fl about twice as large, not hyaline-margined; PERIPHERAL FLS: calyx tubular 5-6 mm, contracted at base into an obconic pedicel 0.5-1 mm, the broad-deltate teeth ±0.9 mm; corolla 7-8.2 mm, the lanceolate lobes 2.3-2.4 x 1 mm; androecium 10-merous, 20-29 mm, the stemonozone 1-1.6 mm, the tube 3-5 mm; ovary 2.6-3.5 mm, obovoid truncate, densely puberulent or puberulent only along the ventral suture; style slightly longer than stamens; TERMINAL FL: calyx sessile, deeply campanulate 5.5-6 x 2.8-3.3 mm, the teeth ±1 mm; corolla ±11 mm, the lobes 2.5 mm; androecial tube exserted 1.5-2 mm; ovary rudimentary or similar in shape and size to that of peripheral fl, surrounded by a shallow disc. Pods to 3 per capitulum, curved through ½-1½ circles 9-11 cm diam, the sutural rib slightly enlarged, the finely venulose valves 3.4-4.5 cm broad, to 6 mm thick over seeds, the mesocarp brown-ligneous, not at all granular or mealy; seeds (not seen fully mature) in 2 or 3 rows, ovate-elliptic in outline ±9x5 mm, the seed-coat apparently shiny brown.

Known only from French Guiana, in undisturbed forest near Cayenne (Matoury; Tonnegrande), and between the Sinnamary and Counamama rivers. — Fl. VIII-IX. — Préfontaine (used in cabinetwork and joinery), St Martin jaune.

Enterolobium oldemanii is closely related to E. schomburgkii, with which it shares persistent golden- brown indumentum, dimorphic flowers with a nectary surrounding the truncate ovary, and an androecium of mostly 10 stamens. It differs most noticeably in the size of the flowers, which are about twice as long as those of E. schomburgkii, but also in thick coriaceous stipules, wider leaflets, and overall fewer peduncles per node. Enterolobium schomburgkii is notable for possessing two morphs of fruit, described under the following. The systematic significance of these two morphs is unknown.

It is with pleasure that we name this species in honor of Dr. R. A. A. Oldeman, indefatigable collector of the flora of French Guiana, who is best known for his contribution to the understanding of the architecture of forest trees.