Herbs annual, 70-160(-200) cm tall, more branched, strongly aromatic, sparsely puberulous, soon glabrous. Petiole of middle leaves 1-2 cm long, blade glandular-punctate, lowermost cauline leaves ovate or triangular-ovate, 3-7×2-6 cm, 3(-4)-pinnately parted, segments 5-8(-l0) pairs, ultimate lobes deeply serrate, teeth triangular, 1-2×0.5 mm, midrib obviously prominent on upper surface, rachis narrowly winged, not serrate or remotely serrate; middle leaves 2(-3)-pinnately and pectinately parted; uppermost leaves and leafy bracts l(-2)-pinnately parted. Heads numerous, globose, 1.5-2.5 mm in diam., nodding, in broad, pyramid shaped paniculate inflorescences. Outer florets 10-18. Central florets 10-30, dark-yellow or yellow. Achenes ellipsoid-ovoid. Fl. and fr. Aug-Sep.
TAIPEI: Tansui, Li 786. HSINCHU: Shimada 9354. TAINAN: Tsang 40.
Widely distributed in Eurasia, northern. Africa, North America and China. Taiwan, not collected for half a century.
Contains essential oils, in which "qing hau su, C15H22O5", arteannuin I, II, cinereole, camphor, artemisia ketone are included. Well known for antiphlogistic, antifebrile and haemostatic uses, especially effective for curing malaria.
