Rheum hotaoense C. Y. Cheng & T. C. Kao

Herbs large, 0.8-1.5 m tall. Rhizomes and roots brown-yellow, stout. Stem straight, glabrous, muricate near nodes. Petiole of basal leaf 17-25 cm, glabrous or muricate; leaf blade dark green or blue-green, ovate-cordate or broadly ovate, large, 25-40 × 23-28 cm, glabrous, basal veins 5, base cordate, margin sinuolate, apex obtuse or acute. Stem leaves shorter petiolate, ovate or ovate-triangular, smaller; ocrea 5-8 cm, clasping. Panicle large, more than 2-branched; rachis and branches glabrous, papilliferous only near nodes. Pedicel 4-5 mm, slender; jointed below middle. Flowers large. Tepals 6, outer 3 subequal to inner 3, elliptic, 2-2.5 mm, sparsely reticulate-veined, abaxially light green with white margin. Stamens equal to perianth. Ovary broadly ellipsoid; styles 3, short; stigmas inflated. Fruit ± orbicular, 7.5-8.5 mm, base circular or slightly cordate, apex retuse; wings 2-2.5 mm wide, with longitudinal veins at middle. Seeds broadly ovoid. Fl. May-Jul, fr. Jul-Sep.

Gansu, Shaanxi, Shanxi.

* Slopes, gullies; 1000-1800 m.