直穗大黄 zhi sui da huang

Rheum aplostachyum Karelin & Kirilov.

Herbs ca. 30 cm tall, stout. Rhizome with large ocrea; roots stout. Petiole of basal leaf nearly subterete, short, 3-6 cm, 5-9 mm in diam., papilliferous; leaf blade broadly ovate or ovate, 12-25 × 10-22 cm, leathery, abaxially densely papilliferous, basal veins 5-7, purple-red, stout, base narrowly cordate or rounded, margin entire, slightly sinuolate, apex obtuse. Panicles 2-5, spiciform; rachis from apex of rhizome, 12-28 cm, 4-8 mm in diam., hollow, 1-3-branched from lower part or not, papilliferous. Pedicel ca. 3 mm, jointed below middle. Tepals yellow-white, narrowly elliptic, outer 3 smaller, 1.8-2 × 0.8-1 mm. Filaments ca. 1.5 mm; anthers broadly elliptic. Fruit ovoid or ellipsoid-ovoid, 1-1.1 cm × 7-8 mm, base subcordate, apex obtuse; wings ca. 2 mm wide, with longitudinal veins at middle. Seeds ovoid. Fl. Jun, fr. Aug-Sep.

Slopes; 2600-4200 m. Xinjiang [Kazakhstan].