泽苦荬 ze ku mai

Lactuca tamagawaensis Makino, Bot. Mag. (Tokyo) 17: 90. 1903; Ixeris chinensis (Thunberg) Kitagawa subsp. arenicola (Makino) Kitamura; Lactuca versicolor (Fischer ex Link) Schultz Bipontinus var. arenicola Makino.

Herbs 15-30 cm tall, perennial, rosulate, glabrous, with a taproot. Stems solitary or few, ± erect, branched mainly apically, distantly leafy. Rosette leaves linear-lanceolate to linear, 6-15 × 0.2-1 cm, undivided, basally attenuate, margin entire or rarely very weakly sinuate-dentate, apex acute. Stem leaves 1-3, similar to rosette leaves but smaller, base semiamplexicaul. Synflorescence laxly corymbiform, with several to some capitula. Capitula with 25-40 florets. Involucre narrowly cylindric, 7-9 mm. Phyllaries abaxially glabrous; outer phyllaries ovate to lanceolate, longest ca. 3 mm, apex acute; inner phyllaries ca. 8, apex ± acute. Florets yellow. Anther tube and style greenish to blackish upon drying. Achene brown, fusiform, 5-6 mm, apex attenuate into a slender ca. 3 mm beak. Pappus ca. 5 mm. Fl. and fr. May-Aug. 2n = 16.

Open gravelly or rocky riverbanks. E Taiwan [Japan, Korea].