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Rheum rhabarbarum
Also called Garden rhubarb, Pie Plant, Pieplant, Wine Plant
Culinary rhubarb is a hardy perennial grown for its sour, fleshy leafstalks, which are cooked into pies, stews and desserts. Its key to success is a cold winter dormancy and a rich, moist soil; only the stalks are eaten, never the leaves.
Rhubarb is the fleshy, edible stalks (petioles) of species and hybrids (culinary rhubarb) of Rheum in the family Polygonaceae, which are cooked and used for food. The plant is a herbaceous perennial that grows from short, thick rhizomes. Historically, different plants have been called "rhubarb" in English. The large, triangular leaves contain high levels of oxalic acid and anthrone glycosides, making them poisonous and therefore inedible. The small flowers are grouped in large compound leafy greenish-white to rose-red inflorescences.
The precise origin of culinary rhubarb is unknown. The species Rheum rhabarbarum (syn. R. undulatum) and R. rhaponticum were grown in Europe before the 18th century and used in folk medicine. By the early 18th century, these two species and a possible hybrid of unknown origin, R. × hybridum, were grown as vegetable crops in England and Scandinavia.
Rhubarb is grown widely, and with greenhouse production it is available throughout much of the year. It needs rainfall and an annual cold period of up to 7–9 weeks at 3 °C (37 °F), known as 'cold units', to grow well. The plant develops a substantial underground storage organ (rhubarb crowns) and this can be used for early production by transferring field-grown crowns to warm conditions. Rhubarb grown in hothouses (heated greenhouses) is called "hothouse rhubarb", and is typically made available at consumer markets in early spring, before outdoor cultivated rhubarb is available. Hothouse rhubarb is usually brighter red, tenderer and sweeter-tasting than outdoor rhubarb. After forcing for commercial production, the crowns are usually discarded. In temperate climates, rhubarb is one of the first food plants harvested, usually in mid- to late spring (April or May in the Northern Hemisphere, October or November in the Southern Hemisphere), and the season for field-grown plants lasts until the end of summer.
The roots and stems contain anthraquinones, such as emodin and rhein. Emodin "represents a genotoxic risk for humans" while rhein is "a compound devoid of genotoxic capabilities". The anthraquinones have been separated from powdered rhubarb root for purposes in traditional medicine, although long-term consumption of anthraquinones has been associated with acute kidney failure.
The rhizomes contain stilbenoid compounds (including rhaponticin), and the flavanol glucosides (+)-catechin-5-O-glucoside and (−)-catechin-7-O-glucoside.
Rhubarb is grown primarily for its sour, fleshy leafstalks, technically known as petioles. The use of rhubarb stalks as food is a relatively recent innovation. This usage was first recorded in 18th- to 19th-century England after affordable sugar became more widely available.
Himalayan Rhubarb · Chinese rhubarb · Chinese rhubarb · Syrian Rhubarb · Rhubarb
Text excerpted from the Wikipedia article Rhubarb by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.
