Mimosa

  • 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

  • Description

    Genus Description - Prickly shrubs, and a few herbaceous, trailing, or unarmed. Leaves clustered from spurs and (or) alternate, bipinnate; leafstalk eglandular, often prickly; pinnae 1-10(-12) pairs; leaflets mostly numerous, symmetric or asymmetric. Stipules acicular to lanceolate, usually inconspicuous, not spinescent. Prickles internodal to subnodal and paired, usually flattened, curved, broadened at base. Inflorescences white to pink-purple, of intercalary, solitary or fascicled, pedunculate heads (less frequently, spikes or racemes) from spurs or leaf axils, and (or) heads terminally aggregated in racemes. Perianth 4-5-merous; calyx tubular to campanulate, the lobes short; corolla lobes fused to near apex, or largely free; stamens 10 or fewer, eglandular; ovary sessile. Legume dehiscent, oblong, compressed, straight to variously curved or twisted; margins straight, undulate to strongly constricted between seeds, often prickly, persistent; valves jointed or not, ultimately separating from the sutures either as a unit or segments.

  • Discussion

    Mimosopsis Britton & Rose CBN x = 13. Literature: Britton & Rose (1928), Correll & Johnston (1970), Isely (1971b). Among the mimosoids, the usually prickly legumes of Mimosa are unique in the separation of the valves from the replum-like sutures at maturity, and the varying levels of segmentation of the valves; their mode of dehiscence is approached primarily by the tetragonal fruits of the derivative Schrankia. In flower, woody Mimosa, with 10 (or fewer) stamens and internodal prickles, is matched by no other genus. Leucaena differs from unarmed Mimosa by its larger heads and leafstalk gland. A flowering, unarmed, herbaceous Mimosa, as M. strigillosa, suggests Desmanthus and Neptunia, but Desmanthus has leafstalk gland(s), and Neptunia lacks the stiff, bulbous-based pubescence of M. strigillosa.

  • Distribution

    Probably 300-400 (600 fide Hutchinson, 1964) species, circumtropical and xerothermic. Ours of s states, Florida to Arizona, n to w Oklahoma and s Colorado; the greatest number xerophytes and of Texas.

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