藏边大黄 zang bian da huang

Rheum emodi Wallich ex Meisner.

Herbs large, 0.7-2 m tall. Rhizomes and roots stout. Stem sulcate, glabrous, pubescent only at nodes. Petiole of basal leaf equal to blade or slightly longer, pubescent; leaf blade ovate-elliptic or broadly ovate, large, 20-50 × 18-40 cm, abaxially pilose, basal veins 5-7, base cordate, margin entire, sinuolate, apex obtuse. Stem leaves ovate, narrow; ocrea large, pubescent, clasping. Panicle large, 2- or 3-branched, densely papilliferous. Pedicel muricate, jointed below middle. Perianth spreading, purple-red, 3-3.5 mm; outer 3 smaller, oblong-elliptic, ca. 1.5 × 1 mm; inner 3 very broadly elliptic or rarely orbicular, ca. 2.5 × 2 mm. Filaments subulate. Ovary rhomboid-obovoid; stigma oblate, muricate. Fruit ovoid-ellipsoid or broadly ellipsoid, 9-10 × 7-8.5 cm, base subcordate, apex retuse or not; wings purple-red, ca. 2.5 mm wide; longitudinal veins near margin. Seeds ovoid. Fl. Jun-Jul, fr. Aug or later.

Grassy slopes; 3400-4300 m. Xizang [India, Myanmar, Nepal, Pakistan, Sikkim].