rhubarb(redirected from Rheum (genus))
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Any plant of the genus Rheum (family Polygonaceae), especially R. rhaponticum, garden rhubarb, and R. officinale or R. palmatum; the last two species or their hybrids, deprived of periderm tissues, dried, and powdered, are used for their astringent, tonic and laxative effects.
1. Any of several plants of the genus Rheum, especially R. rhabarbarum, having long edible green or reddish leafstalks that are usually cooked and sweetened. Also called pie plant.
2. A preparation made from the dried rhizomes and roots of any of several plants of the genus Rheum, especially R. palmatum or R. officinale of East Asia, used as a laxative.