Flora of Barro Colorado Island

Mimosa casta

L., Sp. P1. 518. 1753

Vine, rarely to 5.5 m long, ± glabrous but sometimes with puberulent lower surface of leaflets, armed through­out with stout, recurved thorns. Leaves bipinnate with 1 pair of pinnae; petioles to 10 cm long, eglandular; stipules lanceolate, paired, to ca 5 mm long, striate; leaflets in 3-6 pairs per pinna, inequilateral, elliptic to lanceolate-­oblong, acute at apex, oblique and rounded at base, 1-3 cm long, 7-10 mm wide, setose-ciliate on margins and sometimes on surface below; venation at base palmate. Flowers minute, in globular, white, pedunculate, axillary clusters ca 1-1.5 cm diam, the outermost in each head staminate; floral bracteoles linear-lanceolate, l-2 mm long, pectinate-ciliate at base; calyx obsolete; corolla greenish, 4-lobed, ca 2.5 mm long; stamens (4) 5, 5-8 mm long; style ± equaling stamens. Legumes usually 10-20 in a dense, usually globular cluster, flat, 3-4.5 cm long, ca 1 cm wide, usually   3-6-seeded, each segment distinct, the margins ± sinuate with laterally directed setae. Croat 12821, 13157

Rare; seen only on the shore at the edge of Rear # 8 Lighthouse Clearing. Locally abundant in the Canal Zone along roadsides, especially near water. Flowers and fruits from December to January.

Panama and the northern coast of South America to Brazil; Jamaica and Lesser Antilles. In Panama, known only from tropical moist forest in the Canal Zone.

See Fig. 268.