Cyanthillium  

 Annual herbs. Stems erect, pubescent with T-shaped hairs. Leaves simple, alternate, petiolate; lamina ovate, lanceolate, elliptic or rhombic, pubescent, margin serrate or undulate, apex acute or acuminate, base attenuate, chartaceous. Capitulescences terminal or axillary. Capitula discoid, homogamous, pedunculate, florets bisexual and fertile. Involucre imbricate, persistent. Corollas funnelform, purple to white, actinomorphic, corolla lobes 5. Anthers 5, syngenesious. Styles purple, 2-branched, inner surface covered with stigmatic papillae, outer surface covered with sweeping hairs reaching below style bifurcation. Achenes clavate or turbinate, 5–10-ribbed, carpopodium present. Pappus in one or two series, persistent, the outer ones are shorter than the inner ones. Pollen echinolophate, 3-porate, with micropuncta.  Three species are recognized in Thailand.