掌叶大黄Rheum palmatum Linn.

别名：马蹄黄;曲札;生军;唐古大黄;北大黄;药用大黄;大黄;将军;金大黄;葵叶大黄;阿拉根-给希古纳;掌叶蓼;唐古特大黄;锦纹;天水大黄;肤如;阿拉根－给西古纳;锦纹大黄;掌状大黄;火参;黄良;锦黄;南大黄;香大黄;西宁大黄;西大黄;珠莫萨;Chinese rhubarb;

科名：蓼科 Polygonaceae

属名：大黄属 Rheum

《中国植物志》第25(1)卷184页
  14．掌叶大黄 葵叶大黄 图版46: 5-7
  Rheum palmatum L. Syst. ed. 10: 1010. 1759; Sp. Pl. ed. 2: 531. 1762; Meisn. in DC. Prodr. 14 (1): 32. 1856; 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. 图2, 4-6. 1975; 西藏植物志1: 596. 1983.——Rheum tanguticum auct. non Maxim. ex Regel: Tschirch in Schweiz. Wochenschr. Chem. Pharm. 292. 1910 et Handb. Pharm. 2: 1375. t. 54. 1917.——Rheum potaninii A. Los. in Acta Inst. Bot. Acad. Sci. URSS Ser. 1. Fasc. 3: 78. 1936.
  高大粗壮草本，高1.5-2米，根及根状茎粗壮木质。茎直立中空，叶片长宽近相等，长达40-60厘米，有时长稍大于宽，顶端窄渐尖或窄急尖，基部近心形，通常成掌状半5裂，每一大裂片又分为近羽状的窄三角形小裂片，基出脉多为5条，叶上面粗糙到具乳突状毛，下面及边缘密被短毛；叶柄粗壮，圆柱状，与叶片近等长，密被锈乳突状毛；茎生叶向上渐小，柄亦渐短；托叶鞘大，长达15厘米，内面光滑，外表粗糙。大型圆锥花序，分枝较聚拢，密被粗糙短毛；花小, 通常为紫红色，有时黄白色；花梗长2-2.5毫米，关节位于中部以下；花被片6, 外轮3片较窄小，内轮3片较大，宽椭圆形到近圆形，长1-1.5毫米；雄蕊9, 不外露；花盘薄，与花丝基部粘连；子房菱状宽卵形，花柱略反曲，柱头头状。果实矩圆状椭圆形到矩圆形，长8-9毫米，宽7-7.5毫米，两端均下凹，翅宽约2.5毫米，纵脉靠近翅的边缘。种子宽卵形，棕黑色。花期6月，果期8月。果期果序的分枝直而聚拢。
  产甘肃、四川、青海、云南西北部及西藏东部等省区。生于海拔1500-4400米山坡或山谷湿地，现在甘肃及陕西栽培较广。
  本种根状茎及根供药用。

《Flora of China》 Vol. 5 (2003)
Rheum palmatum  Linnaeus
掌叶大黄   zhang ye da huang
Rheum potaninii Losinskaja; R. qinlingense Y. K. Yang et al.
Herbs large, 1.5-2 m tall, stout. Rhizomes and roots stout. Stem hollow, sulcate, subglabrous or muricate on nodes. Petiole of basal leaf terete, ca. as long as blade, densely papilliferous; leaf blade large, ca. as long as wide, 40-60 cm, abaxially densely pubescent, adaxially sulcate to papilliferous, basal veins 5, base cordate, palmately divided into pinnatisect lobes, apex acuminate or narrowly acute. Stem leaves smaller above; ocrea large, to 15 cm, outside muricate. Panicle large; branches connivent, densely pubescent. Pedicel 2-2.5 mm, jointed below middle. Flowers small. Tepals 6, purple-red, rarely yellow-white, outer 3 elliptic to orbicular, smaller, 1-1.5 mm. Stamens not exceeding perianth. Ovary rhomboid-ovoid; style slightly deflexed; stigma inflated. Fruit oblong-ellipsoid to oblong, 8-9 × 7-7.5 mm, both ends retuse; wings ca. 2.5 mm wide, with longitudinal veins near margin. Seeds brown-black, broadly ovoid. Fl. Jun, fr. Aug.
* Slopes, valleys; 1500-4400 m. Gansu, Hubei, Nei Mongol, Qinghai, Shaanxi, Sichuan, Xizang, Yunnan [cultivated in Russia].
The roots and rhizomes are used medicinally.