Thesaurus

(n) : any plant of the genus Rheum, especially R. Rharbarbarum, having large leaves and long green or reddish acidic leafstalks; the stems are edible, in particular when cooked (although the leaves are mildly poisonous); the dried rhizome and roots of R. Palmatum or R. Officinale, from China, used as a laxative and purgative