島田氏澤蘭

Stems ca. 70 cm long, erect, more or less flexuous, crisp puberulous apically, simple or branching. Median cauline leaves rigid, opposite, ovate-oblong, 7-8×3-4 cm, apex long-acuminate, base rounded or truncate, subsessile, margins serrate, upper surface green, lower surface pale, glandular punctate, densely puberulous on veins on both surfaces, subtrinerved. Inflorescence of more or less compact corymbs; involucre cylindric, 6 mm long, 5-flowered, bracts ca. 12, 2-seriate, rounded or obtuse, outer ones much shorter. Achenes cylindric, 3 mm long, hirsute, Pappus scanty, white, 4 mm long. Chromosome number, 2n = 20 (Peng & Hsu, 1978).

TAIPEI: Yangmingshan, Peng 11540; Wulai, Peng 11540. ILAN: Taipingshan, Suzuki 245. TAICHUNG: Central Cross-Island Highway, Chung 568. NANTOU: Kuankao, Peng 8059. HUALIEN: Chingshuishan, Shimizu & Kao 11989.

Endemic; low to mid elevations.

This species is similar to Eupatorium clematideum and E. ambile, but differs in its 5-flowered heads and subsessile leaves that are glandular-punctate on the lower surface.