Koyamasia calcarea (Kitam.) H. Robinson

Perennial herbs, 20–80 m tall. Stems erect, conspicuously ribbed, puberulous with stipitate glands. Leaves 10–30 by 3–6 cm, ovate or elliptic, margin serrate, apex acute to acuminate, base attenuate, subcoriaceous, upper surface scabrous without glands, lower surface scabrous with whipshaped hairs, and capitate glands, lateral veins 7–10-paired; petioles up to 6 cm long. Capitulescences terminal, usually solitary. Capitula broadly campanulate, 1.5–3 cm long, pedunculate. Receptacle glabrous. Involucres hemispherical, in 6–7 series, 15–20 mm long, 15–20 mm in diam. Phyllaries imbricate, green or purple, margin entire, outer surface puberulous glandular; the outer and the middle ones ovate to lanceolate, acuminate or aristate, upper half strongly reflexed; the inner ones ovate-lanceolate, apex acute. Florets more than 80, corollas funnelform, purple or white, glandular, corolla tubes 5–6 mm long; corolla lobes 2–3 mm long. Anthers 3–4 mm long, apical appendage acute, base obtuse. Styles purple. Achenes subterete, 3.5–4.5 mm long, 10-ribbed, glabrous. Pappus in 1 series of bristles, 1–3 mm long, deciduous.

Thailand: Chiang Mai. Endemic.