rhubarb

(roo′bărb)

[ME. rubarbe]
An extract made from the roots and rhizome of Rheum officinale, R. palmatum, and other species, used as a cathartic and astringent. It is high in oxalic acid. The stems are used as food.

Chinese rhubarb

A member of the rhubarb family investigated as a potential treatment for heatstroke.