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Polygonaceae FAMILY

Rheum × hybridum

Rheum × hybridum

Edibility
4/5
Medicinal
3/5

Safety & Hazards

The plant, but especially the leaf blades, contains several toxic compounds, particularly anthraquinone glycosides, but also soluble oxalates and calcium oxylate crystals[1, 2, 3]. At lower doses these can cause abdominal cramps, burning of the mouth and throat, headache, weakness, nausea and vomiting. In larger, quantities it can lead to coma and death, though generally very large quantities need to be eaten for the plant to be fatal. The leaf stems (petioles) have much lower quantities of toxins and, in several Rheum species are a commonly eaten food. The main caution here are the levels of oxalates. These can lock up certain minerals (especially calcium) in the body, leading to nutritional deficiency. Cooking the plant will reduce the concentration of oxalic acid. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition[4].

Cultivation Details

HabitPerennial
Growth—

Plants are very cold hardy, tolerating temperatures down to at least -20°c[5]. The plant does not like hot summers, however, and is likely to die in warmer climates[6]. A very easily grown plant, tolerant of considerable neglect, it prefers a deep, fertile, moderately heavy, humus rich, moisture retentive, well-drained soil in sun or semi-shade[5, 6]. It succeeds in most soils provided the drainage is good[5] and will grow in the dappled shade of trees so long as there is sufficient side light[PFAF]. It grows well in heavy clay soils. Tolerates acid conditions but prefers a pH in the range 6.5 to 7[5]. Rhubarb is a long-lived and almost indestructible perennial plant[6]. It is often cultivated for its edible leaf stems, there are many named varieties[7, 8]. This species is probably of hybrid origin, Rheum rhaponticum x Rheum rhabarbarun[5]. It hybridizes freely with other members of the genus[5]. Most cultivars produce edible stems from spring to early summer, though a few, such as 'Glaskin's Perpetual' can be harvested throughout the summer. By digging up the roots in the autumn and exposing them to frost, earlier growth will be initiated. These roots can then be transferred to a cold frame or other protected area where they will produce their edible stems in late winter. It is also possible to produce earlier crops outdoors by covering the plants with a layer of straw and an upturned bucket. Plants in this genus seem to be immune to the predations of rabbits[9].

Propagation

Seed - best sown in autumn in a shaded cold frame[5]. 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. This species is a hybrid and will not necessarily breed true to type from seed. However, this does give the opportunity to look for superior plants from amongst the seedlings. Division in early spring or autumn[10, 11]. 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. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Rheum+%C3%97+hybridum>

Pollinators

Wind

References

  1. [1]The Oxford Book of Food Plants. — Harrison. S. Wallis. M. Masefield. G. · Oxford University Press · 1975 · ISBN - ↩︎Good drawings of some of the more common food plants from around the world. Not much information though.
  2. [2]Poisonous Plants in Britain and their Effects on Animals and Man. — Cooper. M. and Johnson. A. · HMSO · 1984 · ISBN 0112425291 ↩︎Concentrates mainly on the effects of poisonous plants to livestock.
  3. [3]Poisonous Plants of North Carolina — http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm ↩︎An excellent concise but comprehensive guide to toxic plants that grow in N. Carolina. It lists even those plants that are of very low toxicity, including several well-known food plants such as carrots and potatoes.
  4. [4]Encyclopaedia of Herbs and their Uses. — Bown. D. · Dorling Kindersley, London. · 1995 · ISBN 0-7513-020-31 ↩︎A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
  5. [5]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
  6. [6]Vegetables — Phillips. R. & Rix. M. · Macmillan Reference Books, London. · 1995 · ISBN 0 333 62640 0 ↩︎Excellent and easily read book with good information and an excellent collection of photos of vegetables from around the world, including many unusual species.
  7. [7]Flora of the USSR. — Komarov. V. L. · Israel Program for Scientific Translation · 1968 · http://www.biodiversitylibrary.org · ISBN - ↩︎An immense (25 or more large volumes) and not yet completed translation of the Russian flora. Full of information on plant uses and habitats but heavy going for casual readers. It can be downloaded from the Internet.
  8. [8]Cornucopia - A Source Book of Edible Plants. — Facciola. S. · Kampong Publications · 1990 · ISBN 0-9628087-0-9 ↩︎Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
  9. [9]Perennial Garden Plants — Thomas. G. S. · J. M. Dent & Sons, London. · 1990 · ISBN 0 460 86048 8 ↩︎A concise guide to a wide range of perennials. Lots of cultivation guides, very little on plant uses.
  10. [10]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
  11. [11]Popular Hardy Perennials. — Sanders. T. W. · Collingridge · 1926 · ISBN - ↩︎A fairly wide range of perennial plants that can be grown in Britain and how to grow them.
  12. [12]Sturtevant's Edible Plants of the World. — Hedrick. U. P. · Dover Publications · 1972 · ISBN 0-486-20459-6 ↩︎Lots of entries, quite a lot of information in most entries and references.
  13. [13]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
  14. [14]Tanaka's Cyclopedia of Edible Plants of the World. — Tanaka. T. & Nakao S. · Keigaku Publishing; Tokyo · 1976 · ISBN - ↩︎The most comprehensive list of edible plants I've come across. Only the briefest entry for each species, though, and some of the entries are more than a little dubious. Not for the casual reader.
  15. [15]Glossary of Indian Medicinal Plants (Including the Supplement). — Chopra. R. N., Nayar. S. L. and Chopra. I. C. · Council of Scientific and Industrial Research, New Delhi. · 1986 · ISBN - ↩︎Very terse details of medicinal uses of plants with a wide range of references and details of research into the plants chemistry. Not for the casual reader.
  16. [16]Medicinal Plants in the Republic of Korea — World Health Organisation, Manila · 1998 · ISBN 92 9061 120 0 ↩︎An excellent book with terse details about the medicinal uses of the plants with references to scientific trials. All plants are described, illustrated and brief details of habitats given.
  17. [17]The Encyclopedia of Medicinal Plants — Chevallier. A. · Dorling Kindersley. London · 1996 · ISBN 9-780751-303148 ↩︎An excellent guide to over 500 of the more well known medicinal herbs from around the world.
  18. [18]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
  19. [19]Encyclopaedia of Medicinal Plants. — Chiej. R. · MacDonald · 1984 · ISBN 0-356-10541-5 ↩︎Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.
  20. [20]Edible and Medicinal Plants. — Launert. E. · Hamlyn · 1981 · ISBN 0-600-37216-2 ↩︎Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.
  21. [21]The Herb Book. — Lust. J. · Bantam books · 1983 · ISBN 0-553-23827-2 ↩︎Lots of information tightly crammed into a fairly small book.
  22. [22]Alpine Plants of China. — Zhang Jingwei. · Gordon & Breach. New York. · 1982 · ISBN 0-677-60190-5 ↩︎A lovely book with nice pictures. Gives habitats and some details of plant uses.
  23. [23]Economic Botany. — Hill. A. F. · The Maple Press · 1952 · ISBN - ↩︎Not very comprehensive, but it is quite readable and goes into some detail about the plants it does cover.
  24. [24]Handbook of Chinese Herbs and Formulas. — Yeung. Him-Che. · Institute of Chinese Medicine, Los Angeles · 1985 · ISBN - ↩︎An excellent Chinese herbal giving information on over 500 species. Rather technical and probably best suited to the more accomplished user of herbs.
  25. [25]Herbs — Phillips. R. & Foy. N. · Pan Books Ltd. London. · 1990 · ISBN 0-330-30725-8 ↩︎Deals with all types of herbs including medicinal, culinary, scented and dye plants. Excellent photographs with quite good information on each plant.
  26. [26]The Complete Homeopathy Handbook. — Castro. M. · Macmillan. London. · 1990 · ISBN 0-333-55581-3 ↩︎A concise beginner's guide to the subject. Very readable.
  27. [PFAF]Plants for a Future — pfaf.org ↩︎