Perennial herbs from a long deep tap-root. Stems erect, grooved, 40-110 cm tall, with stiff spreading-ascending branches, hirsute or nearly glabrous. Lower leaves oblanceolate, petiolate, toothed or more often pinnatifid, 8-25×1-7 cm, becoming reduced, sessile, and entire or toothed upwards. Heads 2.5-4 cm across, terminal on somewhat thickened stalk and in subsessile clusters of 2 or 3 in axils of upper leaves. Flowers large, bright blue, pink or rarely white. Involucre green, 9-15 mm long, outer bracts ca. 8, inner bracts ca. 5, twice as long as outer. Achenes 2-3 mm long, minutely cross-rugulose, unequally several-nerved, broadly rounded on back; pappus of many minute, fimbriate scales. Chromosome number, 2n = 18.
TAOYUAN: Taiwan Livestock Research Institute, Yangmei Branch, Peng 3145. TAINAN: Taiwan Livestock Research Institute, Hsinhua, Peng 3162.
Native of northern Europe, widely naturalized in North America; Taiwan, introduced concomitantly with seeds of Trifolium alexandrinum L. and naturalized in pastures at low elevations (Peng, 1978).
