Acanthospermum
Schrank
Herbs, annual, dichotomously branched, pubescent. Leaves opposite, simple or
pinnatifid. Inflorescence of solitary heads in the axils or at forks of branches. Heads
radiate, small, subsessile to sessile. Involucral bracts biseriate; outer elliptic-ovate,
foliaceous; inner completely enveloping ray achenes. Receptacle convex; pales
membranous. Ray florets 5 - 6; corolla yellow, emarginate or tridentate at apex; tube
equalling the corolla or slightly shorter. Disc florets many; corolla campanulate, 5-lobed.
Anthers cordate-saaittate. Style clavate, obtuse, hispidulous, undivided. Achenes of ray
florets trigonous, slightly compressed, enveloped by inner involucral bracts, tough, echinate with straight or uncinate prickles. Pappus absent.
Distributed in W. Indies, S. America and Madagascar; ca 10 species, 1 in India.
Literature. BLAKE. S.F. (1921). Revision of the genus Acanthospermuim Contr. U.S. Nat. Herb. 20: 383-392.
Distributed in W. Indies, S. America and Madagascar; ca 10 species, 1 in India.
Literature. BLAKE. S.F. (1921). Revision of the genus Acanthospermuim Contr. U.S. Nat. Herb. 20: 383-392.