Kirkman, L.K. (1981)
Taxonomic revision of Centratherum and Phyllocephalum (Compositae: Vernonieae) Rhodora 83 14
Description of the genus
Annual or perennial herbs or small shrubs. Leaves alternate. Inflorescence terminal on axillary branches. Capitula hemispherical, solitary or in clusters of 2-3, homogamous; disk florets bisexual, purple to blue. Phyllaries in several series; outer leaf-like, inner membranous. Receptacular scales 0. Achenes 8-10-ribbed. Pappus a row of bristles.