Cyanthillium Blume, Bidjr. Fl. Ned. Ind. 15: 889. 1826.

Bunwong, Sukhonthip, Chantaranothai, Pranom & Keeley, Sterling C., 2014, Revisions and key to the Vernonieae (Compositae) of Thailand, PhytoKeys 37, pp. 25-101 : 57-58

Cyanthillium Blume, Bidjr. Fl. Ned. Ind. 15: 889. 1826.

Type.

Cyanthillium villosum Blume. Bijdr. Fl. Ned. Ind. 15: 889. 1826.

Description.

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.

Key to the species

1	Pappus in 2-series; capitula narrowly campanulate with 25-30 florets	2
-	Pappus in 1-series; capitula subglobose with 80-120 florets	Cyanthillium patulum
2	Herbs up to 1 m tall, stems and involucres sericeous; achene indistinctly ribbed	Cyanthillium cinereum
-	Herbs up to 2 m tall, stems and involucres pilose-villose to tomentose; achene with distinct 5-8 ribs	Cyanthillium montanum