Rheum palmatum (Chinese or Turkey rhubarb).

Close-up of palmate leaf. Rheum officinale, R. palmatum, and other species of Polygonaceae contain chrysophanic acid, rhein, emodin (purgative anthraquinone formerly used as a laxative, but is now used mainly as tool in toxicity studies), and other anthraquinones. Has also been used extensively in liquor distilling because of its pleasant aroma and digestive qualities. Jams and jellies have been made using the leaf petioles as a basis; these have a slight laxative quality. The purgative effect is similar to senna and alder buckthorn.