(Standl.) Swart, Recueil Trav. Bot. Néerl. 39:426.1942
Protium asperum Standl.
Functionally dioecious tree, 25-50 m tall, to ca 75 cm dbh, weakly buttressed, the base becoming very roughened and warty; outer bark hard, dark brown; inner bark granular, tan; sap with faint, pleasant aroma (not characteristically burseraceous). Leaves deciduous, imparipinnate; petioles flat above, with a raised marginal rib; rachis triangulate on upper surface, rounded below; petiole and rachis shortly pubescent; leaflets 7-11 (to 19 on juveniles), oblong-ovate to oblong-elliptic, acuminate, cuneate to cordate at base (sometimes inequilateral on lateral leaflets), 10-20 (30) cm long, 4-6 (12) cm wide, asperous and scabridulous on both surfaces, sparsely hispidulous below especially on veins, stiff, the margins entire and ± undulate; lateral veins prominent below. Flowers 3-parted, functionally unisexual, in terminal panicles to 29 cm long, usually in dense glomerules, the branches sharply angulate, densely floriferous, hispidulous; pedicels to 4 mm long at anthesis, broadened apically, flattened; calyx sericeous inside, ca 2.7 mm long, caducous; corolla ± urceolate, ca 5 mm long, dull red (tinged with green in pistillate flowers), trilobate, the lobes acute, divided ca halfway to base in staminate flowers and one-fourth to three-fourths the way to base in pistillate flowers; stamens 6 (rarely 10), almost sessile (abortive in pistillate flowers); filaments strap-shaped; anthers oblong, ca 2 mm long, introrse; ovary ± ovoid, glabrous, 2-2.7 mm long at anthesis (reduced in staminate flowers); styles 2, short and thick. Fruits drupaceous, ovoid, ca 1 cm long, blunt or rounded at apex, smooth (drying ± wrinkled and acute at apex), indehiscent, violet-purple at maturity; pyrenes (1) 2, each 1-seeded. Croat 11667, 11881,13932.
Frequent in the old forest. Flowers in late July and August. The fruits mature during the dry season from January to April. Trees lose all their leaves during the early rainy season, but are renewed soon.
Easily distinguished from all other species by its sand-papery, compound leaves with the petiole flattened on the upper surface. Because of the differences in stamen size and condition of the ovary, the sex of any tree can be determined in the field by fallen flowers. Staminate flowers usually fall soon after the pollen has been shed, in most cases with the corolla still attached.
Fruits are probably consumed whole by large birds and mammals, since there is relatively little mesocarp. Known only from Panama; characteristic of tropical wet forest, principally on the Atlantic slope (Tosi, 1971); known also from tropical moist forest in the Canal Zone, Bocas del Toro, and Panama and from premontane wet forest in the Canal Zone (Pipeline Road).
See Fig. 304.