Common Name: Rhubarb

General Information

Rheum rhaponticum is a herbaceous perennial plant growing from a stout, woody, rhizomatous rootstock; it produces a basal clump of leaves up to on stout petioles that are up to cm long; the plant flowers in the summer, producing stout flowering stems around 150 - 200cm tall, occasionally to 300cm[].
The plant is harvested from the wild for local use as a food, medicine and source of materials.

Known Hazards

The plant, but especially the leaf blades, contains several toxic compounds, particularly anthraquinone glycosides, but also soluble oxalates and calcium oxylate crystals[, , ]. 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[].

Botanical References

,

Range

Southeast Europe - Bulgaria

Habitat

Wet mountain rocks in Europe[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	1.20 m
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

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

Edible Uses

Leaf stem - raw or cooked[, , ]. An acid flavour, they are used as a fruit substitute in tarts etc[].

The young flower pouch, harvested before the flowers open, is said to form a dish of great delicacy[].

Medicinal

Rhubarb 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[]. The main species used is Rheum palmatum. Though the chemistry varies slightly, this species is used interchangeably[]. Another report says that this species contains only small quantities of the medicinally active compounds and so it is only used as a mild laxative[].

The root is anticholesterolemic, antiseptic, antispasmodic, antitumor, aperient, astringent, cholagogue, demulcent, diuretic, laxative, purgative, stomachic and tonic[, , , , , ]. Small doses act as an astringent tonic to the digestive system, whilst larger doses act as a mild laxative[]. 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[].
Externally, the root is used in the treatment of burns[].
This remedy is not prescribed for pregnant or lactating women, nor for patients with intestinal obstruction[].
The roots are harvested in October from plants that are at least six years old, they are then dried for later use[].

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

Agroforestry Uses:

Plants can be grown for ground cover when spaced about 1.8 metres apart each way[].

Other Uses

None known

Propagation

Seed - best sown in autumn in a shaded cold frame[]. 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[, ]. 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.