RHUBARB, WINE PLANT, or PIE PLANT, several species of perennial herbs of the genus Rheum, family Polygonacem They are natives of Asia and eastern Europe and have generally very large radical leaves with thick fleshy petioles and small greenish 'or whitish flowers in racemes or particulate fas cicles which are borne on stout stalks well above the foliage. Several of the •species are valued for bold effects in ornamental garden ing, and some have been used in medicine, but the most important species is the common rhu barb (R. rhaponticum) which has long been cultivated in gardens for its tender, acid, escu lent leaf-stalks, which are largely used for mak ing pies, sauce and preserves in spring, and to a less extent for home-made wine from the juice. The plants are usually propagated by means of divided roots, though seed is also used. They thrive best in rich, light, friable loamy soils, well drained but moist, and given liberal applications of manure of all kinds. The plants should be set not less than three feet apart each way, given clean cultivation until the foliage shades the ground and mulched with stable manure during the winter. When two
years old the stalks may be used freely. They are most easily gathered by bending them down while being pulled. The earliest stalks are ob tamed by inverting a barrel over the plants and heaping manure around it; but for forcing the roots are dug in autumn, allowed to freeze, covered with earth or sand in cellars, under greenhouse benches, etc., and watered. After producing a crop die roots are thrown away. Large quantities are cultivated in the Southern truck gardens, but the forced stalks are con sidered superior and generally command higher prices.
rhubarb, formerly popularly used in medicine is supposed to be derived from R. palmatum, but the exact species seems to be still undetermined. Chinese Tartary and parts of China were the principal shipping countries, but Asia Minor was also a producer.