Camchaya gracilis (Thorel ex Gagnep.) Bunwong & H. Rob.

Annual herbs, 50–100 cm tall. Stems erect, terete, inconspicuously ribbed; villose with uniseriate hairs, T-shaped hairs and glands. Leaves alternate, elliptic-oblong, 3–6 by 0.3–1 cm, margin serrate or entire, apex acute, base attenuate, subcoriaceous; upper surface scabrous lacking glands, lower surface scabrous with whip-shaped hairs and capitate glands, lateral veins 8–10-paired; petioles up to 3 mm long. Capitulescences terminal and axillary, corymbose. Capitula campanulate, 8–10 mm long, pedunculate. Receptacle flat, 2–3 mm in diam., glabrous. Involucres campanulate, in 4–5 series, 7–8 mm long, 6–7 mm in diam. Phyllaries imbricate, light green or purple, margin entire without spines, outer surface arachnoid, glandular; the outer ones ovate, apex acute to acuminate; the inner ones ovate-lanceolate, apex acute to acuminate. Florets 50–70; corollas funnelform, purple, puberulous, glands capitate; corolla tubes 3–5 mm long; corolla lobes 2–3 mm long. Anthers ca. 2 mm long, apical appendage acute, base rounded. Styles purple, 5–7 mm long, branches 1.5–2 mm long. Achenes obovate, ca. 2 mm long, puberulous with twin hairs and capitate glands, 4–5-ribbed, carpopodium absent. Pappus 1–2 mm long in 1 series, frequently deciduous or lacking.

Thailand: Ubon Ratchathani. Laos.