The Medicinal Root of the Barbarians

Habit: Imposing perennial herbaceous plant, capable of reaching 2–3 metres in height during flowering. Leaves: The distinctive element of the species because of their exceptional size (4–10 dm). The petiole is robust and about as long as the blade. The latter is cordate and shows palmate venation with 3 main veins (plus 2 smaller basal ones). The margin is deeply incised into numerous acute lobes, giving the leaf its typical hand-like shape. Flowers: Gathered in a large branched panicle whose axis is covered by slight pubescence. The flowers are small but numerous, characterised by an intense red-violet colour. Fruits: An obcordate achene, provided with three violet membranous wings that facilitate wind dispersal. Flowering: May–July.

Chorological type: Asian. Distribution in Italy: It is not a spontaneous species; it is introduced and cultivated mainly in botanical gardens or private gardens for ornamental and medicinal purposes. Habitat: It prefers deep soils rich in organic matter and cool climates, between 800 and 1500 m a.s.l.

Generic name (Rheum): Derived from the Greek term rheu (root); the ancient expression rheu barbarum literally meant “root of the barbarians,” from which the Italian term rabarbaro is derived. Specific name (palmatum): From the Latin palma (palm of the hand), referring to the deep incision of the leaf lobes that reproduces the shape of an open hand.

Chinese rhubarb boasts a millenary history, being cited in Chinese medical texts as early as 2700 BC and once a highly precious commodity along the Silk Road. The rhizomes are rich in anthraquinone derivatives and tannins, which confer biphasic properties: at low doses they act as digestive and astringent remedies, while at higher doses they have a powerful laxative and cathartic effect. It also has depurative and cholagogue virtues (stimulating bile production). In culinary use, only the fleshy petioles with their pleasantly sour taste are employed, especially in Anglo-Saxon pastry-making for pies, compotes, and desserts. However, its versatility also allows its use in savoury recipes, starters, and first courses. It is essential to remember that the leaf blades must not be eaten, since they contain high concentrations of oxalic acid, potentially toxic.