Perennial herbs; stems slender, long creeping above ground, branched, leafy. Radical and cauline leaves yellowish green, linear, lance-linear, oblanceolate to spatulate-elliptic, entire, loosely toothed, to deeply pinnatifid, 4-20×0.4-4 cm, apex attenuate-acuminate, base attenuate, petiole 1-8 cm long. Scapes 10-30 cm long, sometimes with a single leaf. Heads 1-5, 20-24 flowered, 2.5-4 cm across, peduncled; involucre 12-14 mm long, outer bracts calyculate, ovate to ovate-oblong, 2-4(-6) mm long. Corolla yellow, 10-20×3 mm. Achenes ca. 7-8 mm long, narrowly fusiform, slightly incurved, brown, deeply 10-sulcate, beak 3-3.5 mm long. Pappus 6-8 mm long.

TAIPEI: Juifang, Leu 394; Keelung, Peng 4902; Pitouchiao to Aoti, Leu 394; Wanli, Wang 971. ILAN: Toucheng, Peng 13829; Tongkang, Peng 7739. TAOYUAN: Shahlun, Peng 7716.

Japan, Korea and China. Taiwan, sandy seashores in the north.

Ixeris debilis is widely distributed in eastern Asia, mainly along seashores. It is extremely variable in leaf shape and size. Kitamura (1934, 1956) differentiated subsp. debilis, subsp. litoralis, subsp. liukiuensis and subsp. tirfida for plants of this complex, which was followed by Pak & Kawano (1992). We agree with Yahara (1995) that these taxa are morphological indistinguishable from the typical subspecies because there are many intermediates. Recognition of these infraspecific taxa is not warrented.