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Polygonaceae FAMILY

Rheum webbianum

Rheum webbianum

Edibility
2/5
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—

Rheum webbianum is a moderately cold-hardy plant, tolerating winter temperatures that can fall to about -20°c[5]. Rheum species generally prefer a deep, fertile, moderately heavy, humus rich, moisture retentive, well-drained soil in sun or semi-shade[5]. They grow well along the woodland edge or amongst large shrubs[5]. They succeed in heavy clay soils. Plants in this genus seem to be immune to the predations of rabbits[6]. Hybridizes freely with other members of this genus[5].

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. Division in early spring or autumn[7, 8]. 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+webbianum>

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]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.
  7. [7]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 ]).
  8. [8]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.
  9. [9]Flora of China — Missouri Botanical Garden Press; St. Louis. · 1994 · http://flora.huh.harvard.edu/china/ ↩︎An excellent, comprehensive resource in 25 volumes. In addition to the botanical information the flora also gives basic information on habitat and some uses. An on-line version is also available.
  10. [10]Indian Medicinal Plants; An Illustrated Dictionary — Khare C.P. (Ed.) · Springer-Verlag Berlin/Heidelberg · 2007 · ISBN 978-0-387-70637-5 ↩︎
  11. [11]Ethnic Food Plants and Ethnic Food Preparation in Western and Central Himalayas — Ballabh B. & Pullaiah T. · Apple Academic Press; Oakville, Canada · 2018 · ISBN 978-1-77188-550- ↩︎
  12. [12]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
  13. [13]The Gardener's Assistant. — Thompson. B. · Blackie and Son. · 1878 · ISBN - ↩︎Excellent general but extensive guide to gardening practices in the 19th century. A very good section on fruits and vegetables with many little known species.
  14. [14]Plants for Man. — Schery. R. W. ↩︎Fairly readable but not very comprehensive. Deals with plants from around the world.
  15. [15]A Dictionary of Plants Used by Man. — Usher. G. · Constable · 1974 · ISBN 0094579202 ↩︎Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
  16. [16]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.
  17. [17]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.
  18. [18]The Complete Homeopathy Handbook. — Castro. M. · Macmillan. London. · 1990 · ISBN 0-333-55581-3 ↩︎A concise beginner's guide to the subject. Very readable.
  19. [19]Non-Timber Forest Products of Nepal Himalaya - database of some important species found in the mountain protected ar — Ghimire S.K. et al · WWF Nepal, Kathmandu, Nepal · 2008 · ISBN 978-99946-837-9-6 ↩︎
  20. [PFAF]Plants for a Future — pfaf.org ↩︎