Rheum palmatum

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Rheum palmatum
Light:Full Sun Part Shade
Moisture:Mesic
Hardiness:7
Soil pH:5.6-8.4
Height:10'
Width:7'
Blooms:Early Summer-Mid Summer
Native to:
Edible Rating:PFAF Edibility RatingPFAF Edibility RatingPFAF Edibility Rating
Medicinal Rating:PFAF Medicinal RatingPFAF Medicinal RatingPFAF Medicinal Rating
Tea:Yes
Poisonous

Rheum palmatum (common name: turkey rhubarb)

Propagation: Seed - best sown in autumn in a shaded cold frame[1]. The seed can also be sown in spring in a cold frame. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse or cold frame for their first winter, planting them out in the spring.

Division in early spring or autumn[2][3]. Divide up the rootstock with a sharp spade or knife, making sure that there is at least one growth bud on each division. Larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer.

Cultivation: Prefers a deep, fertile, moderately heavy, humus rich, moisture retentive, well-drained soil in sun or semi-shade[1]. Grows well in heavy clay soils. Plants can be grown in quite coarse grass, which can be cut annually in the autumn[4].

Hardy to at least -15°c[1].

A very ornamental plant[2], there is at least one named variety[5].

Hybridizes freely with other members of this genus[1].

The sub-species R. palmatum tanguticum is cultivated as a medicinal plant in China[6][7], it was at one time a popular purgative in Europe[8].

Plants in this genus seem to be immune to the predations of rabbits[4].

Turkish rhubarb is a good companion plant for columbine (Aquilegia spp)[9].

Range: E. Asia - N.W. China in Yunnan, W. Sichuan, E. Xizang and Gansu.

Habitat: Scrub and rocky places and by streams, 2500 - 4000 metres. Slopes and valleys at elevations of 1500 - 4400 metres in western and northern China[10].

Edibility: Leaf stem - raw or cooked[11][12][13][5]. The stem is superior in flavour to the common rhubarb and quite tender[11]. An acid flavour, it is sometimes used as a cooked fruit substitute[K].

Medicinal: Chinese rhubarb, called Da Huang in China, has a long and proven history of herbal usage, its main effect being a positive and balancing effect upon the whole digestive system. It is one of the most widely used herbs in Chinese medicine[14]. It has a safe and gentle action, safe even for children to use[15]. The plant is also part of a North American formula called essiac which is a popular treatment for cancer. Its effectiveness has never been reliably proven or disproven since controlled studies have not been carried out. The other herbs included in the formula are Arctium lappa, Ulmus rubra and Rumex acetosella[15].

The root is anticholesterolemic, antiseptic, antispasmodic, antitumor, aperient, astringent, cholagogue, demulcent, diuretic, laxative, purgative, stomachic and tonic[16][12][17][18][19][20][21][14]. The roots contain anthraquinones, which have a purgative effect, and also tannins and bitters, which have an opposite astringent effect[7]. When taken in small doses, it acts as an astringent tonic to the digestive system, whilst larger doses act as a mild laxative[22][7]. The root is taken internally in the treatment of chronic constipation, diarrhoea, liver and gall bladder complaints, haemorrhoids, menstrual problems and skin eruptions due to an accumulation of toxins[14]. This remedy is not prescribed for pregnant or lactating women, nor for patients with intestinal obstruction[14]. Externally, the root is used in the treatment of burns[14]. The roots are harvested in October from plants that are at least six years old, they are then dried for later use[16].

A homeopathic remedy is prepared from the dried root[22]. This is used especially in the treatment of diarrhoea in teething children[22].

Usage: An insect spray is made from the leaves[9]. This spray is also said to help prevent clubroot of brassicas[9].

The cultivar 'Atrosanguineum' can be used as a ground cover plant in a sunny position[23]. Other forms can also be used, they are best planted about 1.8 metres apart each way[24].

Pollinators: Wind

Soil: Can grow in medium and heavy soils.

Drainage: Prefers well drained soil.

Seed Ripens: Mid Summer-Early Fall

Flower Type: Hermaphrodite

Heavy Clay: Grows in heavy-clay soils.

Known Hazards: The leaves are poisonous[18]. This report probably refers to high levels of oxalic acid found in the leaves. Perfectly safe in moderate quantities, oxalic acid can lock up certain minerals (especially calcium) in the body, leading to nutritional deficienc

Links

References

  1. ↑ 1.0 1.1 1.2 1.3 Huxley, Anthony. The New Royal Horticultural Society Dictionary of Gardening. MacMillan Press, 1992.
  2. ↑ 2.0 2.1 Chittendon, Fred. RHS Dictionary of Plants. Oxford University Press, 1951.
  3. ↑ Sanders, Thomas. Popular Hardy Perennials. Collingridge, 1926.
  4. ↑ 4.0 4.1 Thomas, Graham. Perennial Garden Plants. J. M. Dent & Sons, 1990.
  5. ↑ 5.0 5.1 Facciola, Stephen. Cornucopia - A Source Book of Edible Plants. Kampong Publications, 1990.
  6. ↑ Usher, George. A Dictionary of Plants Used by Man. Constable, 1974.
  7. ↑ 7.0 7.1 7.2 Phillips, Roger. Herbs. Pan Books, 1990.
  8. ↑ Tutin, Tom et al.. Flora Europaea. Cambridge University Press, 1964.
  9. ↑ 9.0 9.1 9.2 Riotte, Louise. Carrots Love Tomatoes. Garden Way, 1978.
  10. ↑ Flora of China. 1994.
  11. ↑ 11.0 11.1 Hedrick, Ulysses. Sturtevant's Edible Plants of the World. Dover Publications, 1972.
  12. ↑ 12.0 12.1 Chiej, Roberto. Encyclopaedia of Medicinal Plants. MacDonald, 1984.
  13. ↑ Tanaka, Tyōzaburō. Tanaka's Cyclopaedia of Edible Plants of the World. Keigaku Publishing, 1976.
  14. ↑ 14.0 14.1 14.2 14.3 14.4 Bown, Deni. Royal Horticultural Society Encyclopaedia of Herbs and Their Uses. Dorling Kindersley, 1995.
  15. ↑ 15.0 15.1 Chevallier, Andrew. The Encyclopedia of Medicinal Plants. Dorling Kindersley, 1996.
  16. ↑ 16.0 16.1 Grieve, Margaret. A Modern Herbal. Penguin, 1984.
  17. ↑ Launert, Edmund. Edible and Medicinal Plants. Hamlyn, 1981.
  18. ↑ 18.0 18.1 Lust, John. The Herb Book. Bantam Books, 1983.
  19. ↑ Jingwei, Zhang and Ching-Wei Chang. Alpine Plants of China. Horizon Books, 1982.
  20. ↑ Hill, Albert. Economic Botany. The Maple Press, 1952.
  21. ↑ Yeung, Him-Che. Handbook of Chinese Herbs and Formulas. Institute of Chinese Medicine, 1985.
  22. ↑ 22.0 22.1 22.2 Castro, Miranda. The Complete Homeopathy Handbook. Macmillan, 1990.
  23. ↑ Brickell, Christopher. The RHS Gardener's Encyclopedia of Plants and Flowers. Dorling Kindersley Publishers, 1990.
  24. ↑ Thomas, Graham. Plants for Ground Cover. Everyman, 1990.


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