双花华蟹甲 shuang hua hua xie jia

Senecio davidii Franchet, Nouv. Arch. Mus. Hist. Nat., sér. 2, 10: 40. 1887 ["Davidi"]; Cacalia davidii (Franchet) Handel-Mazzetti; C. didymantha (Dunn) Handel-Mazzetti; S. didymanthus Dunn; S. tuberivagus W. W. Smith.

Stems robust, 8-10 mm in diam. at base, fistulose, to 150 cm tall, distinctly sulcate when dry, glabrous. Radical and lower stem leaves fallen by anthesis, petiolate; middle stem leaves with petiole 3-5 cm, sparsely puberulent or glabrous, basally expanded and subamplexicaul; blade of middle stem leaves abaxially pale green or purplish, adaxially dark green, triangular or pentagonal, 8-15 × 9-20 cm, leathery, abaxially fulvous puberulent on veins or glabrescent, adaxially sparsely hispidulous or subglabrous, basally palmately 3-5-veined, base truncate or weakly cordate, apex acute, mucronate-dentate. Upper stem leaves smaller; uppermost leaves shortly petiolate, ovate-triangular. Capitula small, numerous, arranged in terminal compound paniculoid thyrses; axes and peduncles fulvous puberulent; peduncles short, 2-5 mm, usually with 2 or 3 linear or linear-lanceolate bracteoles. Involucres cylindric, 8-10 × 1.5-2 mm; phyllaries 4 or 5, linear-oblong, 0.5-1.5 mm wide, with obtuse minutely puberulent tips and narrow scarious margins, glabrous, inconspicuously 3-5-veined. Ray florets 2; corolla yellow, ca. 8 mm with ca. 5.5 mm tube; lamina oblong-linear, 10-12 × 0.5-1.5 mm, 4-veined, apically minutely 2-dentate. Disk florets 2, rarely 4; corolla yellow, ca. 8 mm, with ca. 2 mm tube and funnelform limb; lobes 5, lanceolate, ca. 1.5 mm, apically acute. Anthers linear-oblong, ca. 3.5 mm, shortly caudate; appendages ovate-oblong. Style branches ca. 1.5 mm, papillose, obtuse. Achenes cylindric, ca. 3 mm, glabrous, ribbed. Pappus white, sometimes rubescent, 5-6 mm. Fl. Jul-Aug, fr. Oct.

● Grassy slopes, cliffs, roadsides, forest margins; 900-3200 m. Shaanxi, Sichuan, Xizang, Yunnan.