Mimosa pigra L.

• Authority

  Isley, Duane. 1973. Leguminosae of the United States: I. Subfamily. Mimosoideae. Mem. New York Bot. Gard. 25 (1): 1-152.

• Family

  Mimosaceae

• Scientific Name

  Mimosa pigra L.

• Description

  Species Description - A prickly, thicket-forming, pubescent shrub, 1-4 m. Pubescence of: (1) bulbous-based, tapering spicules, 1-2 mm on stems and leaves, to 3.5 mm on legumes, (2) puberulence, .1-.4 mm. Pinnae 4-6 pairs; leaflets 15-25 pairs, crowded, oblong, 3-4 mm, nearly symmetric. Prickles nearly straight, broad, whitish, primarily of stems. Flowers in fascicled, fragrant, bright pink (fading white) ovoid to capitate heads ca 1 cm diam, in axillary and in terminal racemes. Calyx ca 1 mm; corolla ca 2 mm. Legume oblong, straight, 4-6 cm long, ca 1 cm wide; valves conspicuously pubescent-bristly with a velutinous undercoating, breaking at maturity into 7-15 narrow segments leaving the persistent, empty margins.

• Discussion

  The U.S. form of M. pigra, var. berlandieri, is distinguished from tropical American M. pigra as follows. Key to Varieties of Mimosa pigra 1. Stem and leafstalks abundantly prickly; pinnae 6-12 pairs, leaflets ca 6 mm; surface of legume valves hidden by pubescence until maturity. var. pigra. 1. Stem sparsely prickly and leafstalks usually not; pinnae 4-6 pairs, leaflets 3-4 mm; surface of legume valves not hidden by pubescence. var. berlandieri.

• Distribution

  S Texas. Tropics and warm regions of both hemispheres.