1. Petasites tatewakianus Kitamura, Acta Phytotax. Geobot. 9: 64. 1940.
掌叶蜂斗菜 zhang ye feng dou cai
Rhizomes long, creeping, 4-10 mm. Scapes of male florets ca. 50 cm tall, of female florets over 50 cm tall, arachnoid-crisped throughout. Bracteal leaves sessile, ovate-oblong, 4-4.5 × 1.5-1.6 cm, densely crisped, parallel veined, margin entire, apex obtuse. Upper bracts oblong, rudimentary. Leaves all basal, long petiolate; petiole 20-30 cm, initially crisped-villous, glabrescent; blade adaxially green, reniform or orbicular-reniform, 19-23 × 20-40 cm, or broader, palmately dissected (not to middle); segments 7-9, cuneate, terminal segment usually 3-lobed, with mucronulate teeth, abaxially densely white crisped, hairs thin, adaxially crisped-puberulent. Male capitula corymbose or paniculate; peduncles 4-8 cm. Synflorescences of male capitula ca. 40 cm, heterogeneous; involucres ca. 7 × 10-14 mm; female florets numerous, filiform, ca. 6 mm, apex truncate, style ca. 8 mm, 2-fid; male florets ca. 6.5 mm, tube narrow, ca. 3.5 mm. Female capitula homogeneous or heterogeneous; ray florets female. Central florets male, purplish or white; involucres hemispheric, ca. 10 × 10 mm, base with linear-lanceolate bracts; phyllaries uniseriate, imbricate, narrowly oblong, crisped-pubescent, apex obtuse. Female florets fertile, filiform, ca. 10 mm; lamina ca. 1 mm, style 2-fid. Male florets: corolla tubular, ca. 10.5 mm, tube narrow, ca. 6 mm, lobes ca. 3 mm; anthers basally 2-fid; filaments nodiform dilated; style slightly exceeding corolla, apex clavately dilated, with small ring below stigma 2-fid, puberulent. Achenes cylindric, 3-3.5 mm, glabrous, apex truncate. Pappus in female florets white, 9-12 mm, finely bristly. Pappus in male florets few, ca. 7 mm, bristly. Fl. Jun-Jul.
Sandy and stony banks of forest rivers and streams, forming huge thickets. Heilongjiang [Russia (Far East, Sakhalin)].