Erect or ascending, bushy perennial herb commonly cultivated as an annual, c. 5-45 cm, stem and branches villous when young but soon glabrescent. Leaves narrowly or more broadly elliptical to oblanceolate or rhomboid-ovate, acute or acuminate at the apex, long-attenuate into an indistinctly demarcated petiole below, often purple-suffused and not rarely variegated. Heads axillary, sessile, usually solitary, globose or ovoid, 5-6 mm in diameter. Tepals white, lanceolate, acute, mucronate with the excurrent midrib, the outer 3 prominently 3-nerved below and darker in the nerved area, with a line of minutely barbellate white hairs along each side of this area, the hairs becoming denser towards the base of the tepal; inner 2 tepals shorter, mostly 1-2-nerved. Pseudo-staminodes equalling the filaments, laciniate at the tip.

Type: Cultivated specimen from St. Petersburg Botanic Garden (LE, holotype!).

Said to be a native of tropical America, probably Brazil, now widespread as a bedding plant and exact native area blurred by naturalisation; but no certainly wild specimens have been seen, and the plant may be a cultigen of Alternanthera ficoidea (L.) R. Br. ex Griseb.