Monographs Details: Calliandra
Authority: Isley, Duane. 1973. Leguminosae of the United States: I. Subfamily. Mimosoideae. Mem. New York Bot. Gard. 25 (1): 1-152.
Description:Genus Description - Unarmed, perennial herbs or shrubs. Leaves bipinnate without glands; pinnae 1-several pairs. Stipules small but commonly persistent and evident, striate. Inflorescences in most native kinds of solitary or paired, axillary, few (2-10)-flowered white to pink (red) heads; among cultivated species and local C. schottii, heads may range from axillary to terminally congested and have numerous flowers. Calyx campanulate, shallowly lobed; corolla funnelform, the tube equaling or exceeding lobes; stamens numerous, connate below, much exserted. Ovary sessile. Legume dehiscent, cuneate-oblong or oblanceolate, compressed, not septate; sutures thickened; valves membranous to subwoody, at maturity separating downward from apex along both sutures, and curving outwards.
Possibly 125 species of the tropics and warm regions of both hemispheres. Our native kinds of arid regions, Texas to California; introduced species in cultivation.
CBN possibly x = 8 (counts for only 2 species seen).
Literature: Britton & Rose (1928), Turner (1959), Kearney & Peebles (1960), Correll and Johnston (1970), Isely (1972).
In the United States, native Calliandra is easily recognized by its eglandular leaves, few-flowered heads, and mode of dehiscence of the legumes. The species are primarily of two groups, one suffruticose (C. eriophylla, C. conferta and C. biflora), and the other herbaceous (C. humilis). Neither is clearly understood.