Shrubs or trees, armed, stipules spiny (except P. keyense). Stems and twigs spreading, glabrous or hairy, without resting buds, with or without short shoots (brachyblasts), bark smooth to rough, crown usually rounded. Leaves alternate, even-bipinnate, not sensitive to touch; stipules present; petiolate; pinnae 2(or 4), opposite, extrafloral nectaries present between pinnae and leaflets; leaflets 2, opposite, blade margins entire, surfaces glabrous or glabrescent. Inflorescences pedunculate, 15–50+-flowered, axillary, heads or spikes, forming pseudoracemes; bracts absent or present, glandular. Flowers mimosoid, sessile, valvate; calyx greenish, campanulate or tubular, lobes 5 or 6, calyx and corolla connate; corolla greenish; stamens 15+, monadelphous, connate proximally into a tube, filaments white or pinkish; anthers dorsifixed. Fruits legumes, sessile or stipitate, turgid, recurved to coiled, oblong, without thickened margins, dehiscent, leathery, rugose to reticulate, hairy or glabrous; ± constricted between seeds. Seeds 5–12[–16], elliptic to ovate or obovate in outline, strongly biconvex; aril present. x = 13.

Distribution

s United States, Mexico, West Indies, Central America, n South America, introduced in Asia, Africa, Pacific Islands (Guam, Hawaii, Philippines).

Discussion

Species ca. 20 (3 in the flora).

Selected References

None.

Lower Taxa

Pithecellobium dulce, Pithecellobium keyense, Pithecellobium unguis-cati

Key

1	Stem nodes with conspicuous short shoots; peduncles pubescent, less than 2 cm; aril white or pinkish, covering nearly all of seed.	Pithecellobium dulce
1	Stem nodes without short shoots; peduncles glabrescent or glabrous, (1.5–)1.8–7 cm; aril white or red, covering proximal 1/3 of seed.	> 2
2	Trees, unarmed; peduncles flattened; petioles shorter than rachises; aril red.	Pithecellobium keyense
2	Shrubs or trees, armed; peduncles not flattened; petioles longer than rachises; aril white.	Pithecellobium unguis-cati