Synedrella Gaertner

Herbs, annual, erect, procumbent, branched. Leaves opposite, simple, serrate, pubescent with white hairs, petiolate; petiole winged. Heads fascicled in upper leaf axils; peduncles short with foliaceous bracts. Heads radiate. sessile to subsessile, small. Involucral bracts many; outermost green; inner scarious, narrower. Ray florets 4 - 5; corolla yellow, 2 - 3 dentate. Ovary flattened with broad, erose margins and 2 awns; style branched, slender, pilose. Disc florets many; corolla tubular, 4-lobed, dorsally pubescent. Anthers dark. Ovary oblong, with 2 apical awns and a thick cap; style branches slender, flattened, pilose. Achenes dimorphic; those of ray florets flat with broad, light coloured toothed margins and 2 short apical awns; those of disc florets slender, tuberculate, with· 2 - 3 hard, diverging, strigose awns.

Tropical America, Africa and Mexico; ca 50 species, 2 in India.

KEY TO THE SPECIES

1a. Erect herbs, dichotomously branched; involucral bracts 1-2; achoenss of ray florets dorsally compressed, winged; wings lacorate and spinous

1. Synedrella nodiflora

b. Prostrate herbs, rooting at nodes, irregularly branched; involucral bracts 4; achenes of ray florets slightly compressed, narrowly winged; wings neither lacerate nor spinous

2. Synedrella vialis

List of Lower Taxa