Perennial herbs from short rhizomes. Stems erect, simple, striate, 50-100 cm tall, leafy, branched in upper part. Leaves radical and cauline; radical and lower cauline leaves withering before flowering; median cauline leaves lanceolate to ovate-oblong; apex acuminate to tapering; base narrowly cuneate, decurrent, 11-20(-25)×0.8-2.7 cm, subsessile, margins serrate to dentate. Heads radiate, in compound corymbs; peduncle slender; bracteoles linear. Involucral bracts ca. 4.5-6×1.5 mm, apex brownish purple, ciliate, densely hairy on outer surface, margins scarious. Ray florets 5 or 6, yellow, 11-15×2.8-3 mm, tube 3.5-5 mm long; disc florets 5.5-6.7 mm long. Achenes cylindric, 3.5-4 mm long, glabrous to hairy. Pappus ca. 5 mm long.

ILAN: Nanhutashan, Chen 14; Taipingshan, Peng 10331. HSINCHU: Yuanyanghu, Chen 162. MIAOLI: Tapachienhshan, Peng 8439. NANTOU: Nengkaoshan, Kelley 143-98. KAOHSIUNG: Kuanshan, Chung 1059-A. TAITUNG: Takuanshan, Peng 11718. HUALIEN: Mukuashan, Peng 7359; Chingshuishan, Leu 1808.

Endemic; forest margins, exposed road cuts in forests, and alpine meadows, 1,600 to 3,500 m.

Senecio nemorensis var. dentatus differs from the typical variety in having fewer ray florets (5 or 6 vs. 8-11) and narrower leaves. Separation of S. nemorensis var. dentatus and S. morrisonensis is often difficult. Many variously intermediate forms are observed and recognition of the two taxa is to a large extent arbitrary.