Common Name: Canaigre

General Information

Rumex hymenosepalus is a perennial plant with distinctly tuberous roots and short rhizomes. The stems are usually erect, growing around 25 - 100cm tall[].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It has been harvested on a large scale from the wild for the tannins contained in its roots, and has also been cultivated, both within its native range and in trials in other countries[].

Known Hazards

Plants can contain quite high levels of oxalic acid, which is what gives the leaves of many members of this genus an acid-lemon flavour. Perfectly alright in small quantities, the leaves should not be eaten in large amounts since the oxalic acid can lock-up other nutrients in the food, especially calcium, thus causing mineral deficiencies. The oxalic acid content will be reduced if the plant is cooked. 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

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Range

Western N. America - Montana, Wyoming, California to Utah, south to Baja California, northwest Mexico and Texas

Habitat

Dry sandy places below 1500 metres in California[]. Sandy and rocky places: plains, slopes, stream beds, alkaline soils; at elevations up to 1,700 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	1.00 m
Pollinators	Wind
Cultivation Status	Cultivated, Wild

Cultivation Details

Succeeds in most soils but prefers a deep fertile moderately heavy soil that is humus-rich, moisture-retentive but well-drained and a position in full-sun or part shade[]. Judging by its native range, this plant should succeed in dry soils[].
The plant has been extensively cultivated in the past for the tannin contained in its root[].
Being wind -pollinated, Rumex species usually hybridize readily, especially with other members of the genus they are more closely related to[].

Edible Uses

Young leaves - cooked as a pot-herb[, , , , ]. They are usually cooked in several changes of water to remove the bitter-tasting tannin[].

Leaf stems - cooked[, , ]. Crisp and tart, they are excellent when used in pies like rhubarb[, ]. They are often cooked with sugar, or can be baked and the central portion eaten[].

The stems, harvested before the flowers open, have been boiled to make a drink[].

Seed - raw or cooked[]. It can be ground into a powder, cooked with water to the consistency of a thick gravy and eaten as a mush[, ]. The powder can also be mixed with water, shaped into cakes and baked[].

Root[, ]. Eaten raw by children in early spring[].

Medicinal

An infusion of the stems and leaves has been used as a wash for sores, ant bites and infected cuts[].

The roots are astringent[]. An infusion has been used in the treatment of diarrhoea[]. An infusion has been used as a gargle to treat coughs and sore mouths and throats[]. The root has been chewed in the treatment of coughs and colds[].
The dried, powdered roots have been used as a dusting powder and dressing on burns and sores[].

A tea made from this plant is used to treat colds[, ].

Other Uses

The roots are rich in tannin, the dried root containing about 35 - 60%[, , ]. Wild roots contain more tannin than cultivated roots whilst old roots contain more than young roots[].

Yellow, dark green to brown and dark grey dyes can be obtained from the roots of this plant[, , ]. They do not need a mordant[].

Propagation

Seed - sow spring in situ.
Division in spring.