Polygonaceae Rheum spp.
Source: Magness et al. 1971
Rhubarb is a perennial plant which forms large fleshy rhizomes and large leaves with long, thick petioles, the edible portion. Rhizomes and the crown persist for many years. The leaves grow from the ground in early spring. Leaf blades, which are poisonous, are up to a foot or more in width and length. The edible petioles are up to 18 inches long, 1 to 2 inches in diameter, generally somewhat hemispherical in cross section. Roots are also taken up and bedded in cellars or houses in winter, forcing growth in darkness to produce etiolated leaf-stems, which are much prized.
Production in the U.S.: 3,010 acres reported 1959 census. Possibly 20,000 tons; also in many home gardens.
Use: Fresh as sauce or culinary; also frozen commercially.
Part of plant consumed: Large fleshy leaf petioles only.