紫背蟹甲草 zi bei xie jia cao

Senecio ianthophyllus Franchet, J. Bot. (Morot) 8: 361. 1894; Cacalia ianthophylla (Franchet) Handel-Mazzetti.

Rhizomes short, slender, with few tomentose fibrous roots. Stem solitary, erect or oblique, 20-40 cm tall, slender, glabrous, striate, naked below. Stem leaves usually 2 or 3, crowded at middle part of stem; lower leaves fallen by anthesis, long petiolate; petiole not winged, 5-7 cm, sparsely arachnoid or glabrous; blade abaxially purple-blue or purple, adaxially green, thinly papery, broadly cordate-orbicular or ovate-cordate, 5-14 × 8-11 cm, abaxially sparsely arachnoid, later glabrescent, adaxially sparsely hispidulous, basally 5-7-veined, lateral veins upward furcately branched, veins prominent on both surfaces, base deeply cordate, margin unequally serrate, teeth mucronulate, apex acuminate or caudate. Capitula numerous, usually on one side, arranged in terminal large panicles, synflorescence branches spreading, glabrous or uppermost hispidulous; peduncles 2-4 mm, spreading or pendulous, densely shortly hairy. Involucres pink-purple, cylindric, 12-14 × 1.5-2 mm, glabrous, margin narrowly scarious, apically slightly acute. Florets 5 or 6; corolla yellow, ca. 8 mm; tube shorter than limb; lobes lanceolate. Anthers exserted from corolla, basally caudate. Style branches excurved, truncate, papillose. Achenes cylindric, glabrous. Pappus white, ca. 8 mm. Fl. Jul-Aug.

● Mixed or coniferous forests; 1400-1600 m. Chongqing (Chengkou), W Hubei.

Parasenecio ianthophyllus is easily distinguished by its stem leaves 2 or 3, often crowded at the middle, and blade broadly cordate-orbicular, abaxially blue-purple, with veins conspicuously prominent on both surfaces.