《中国植物志》|| 蓼科 POLYGONACEAE ||掌叶组 Sect. Palmata A. Los. ||鸡爪大黄 Rheum tanguticum Maxim. ex Balf.

15.鸡爪大黄 唐古特大黄
Rheum tanguticum Maxim. ex Regel in Gartenfl. 24: 3. t. 819. 1875; Maxim. ex Balf. in Trans. Bot. Soc. Edinb. 13: 146. 1879; A. Los. in Acta Inst. Bot. Acad. Sci. URSS Ser. 1. Fasc. 3: 77. 1936; 高作经等, 植物分类学报13 (3): 73. 1975.——Rheum palmatum L. subsp. dissectum Stapf. f. rubiflora Stapf. in Curtis's Bot. Mag. 153: t. 9200. 1927.
高大草本，高1.5-2米，根及根状茎粗壮，黄色。茎粗，中空，具细棱线，光滑无毛或在上部的节处具粗糙短毛。茎生叶大型，叶片近圆形或及宽卵形，长30-60厘米，顶端窄长急尖，基部略呈心形，通常掌状5深裂，最基部一对裂片简单，中间三个裂片多为三回羽状深裂，小裂片窄长披针形，基出脉5条，叶上面具乳突或粗糙，下面具密短毛；叶柄近圆柱状，与叶片近等长，被粗糙短毛；茎生叶较小，叶柄亦较短，裂片多更狭窄；托叶鞘大型，以后多破裂，外面具粗糙短毛。大型圆锥花序，分枝较紧聚，花小, 紫红色稀淡红色；花梗丝状，长2-3毫米，关节位于下部；花被片近椭圆形，内轮较大，长约1.5毫米；雄蕊多为9, 不外露；花盘薄并与花丝基部连合成极浅盘状；子房宽卵形，花柱较短，平伸，柱头头状。果实矩圆状卵形到矩圆形，顶端圆或平截，基部略心形，长8-9.5毫米，宽7-7.5毫米，翅宽2-2.5毫米，纵脉近翅的边缘。种子卵形，黑褐色。花期6月，果期7-8月。
产甘肃、青海及青海与西藏交界一带。生于海拔1600-3000米高山沟谷中。
本种根状茎及根供药用。

《Flora of China》|| Polygonaceae || Rheum ||鸡爪大黄 Rheum tanguticum

14. Rheum tanguticum (Maximowicz ex Regel) Maximowicz ex Balfour, Trans. Bot. Soc. Edinburgh. 13(App.): cxlvi. 1879.

鸡爪大黄 ji zhua da huang

Herbs large or short, (0.6-)1.5-2 m tall. Rhizomes and roots yellow, stout. Stem stout, hollow, finely sulcate, glabrous or pubescent. Basal leaves orbicular or broadly ovate, large, 30-60 cm, abaxially pubescent, adaxially papilliferous or muricate, basal veins 5, base subcordate, palmately 5-lobed, middle 3 lobes pinnatisect, apex narrowly acute. Stem leaves few, much parted; ocrea large, abaxially pubescent, clasping. Panicle large; branches connivent. Pedicel 2-3 mm, slender, jointed below middle. Flowers small. Tepals purple-red, rarely light red, orbicular, inner 3 larger, ca. 1.5 mm. Ovary broadly ovoid; style short; stigma inflated. Fruit oblong-ovoid to oblong, 8-9.5 × 7-7.5 mm; wings 2-2.5 mm wide, with longitudinal veins near margin. Seeds black, ovoid. Fl. Jun, fr. Jul-Aug.

* Valleys; 1600-3000 m. Gansu, Qinghai, Shaanxi, Xizang.

One of us (Grabovskaya-Borodina) indicates that this is a synonym of Rheum palmatum.