The reports on medicinal use in [] and [] are for plants growing in China. Since this plant is endemic to Japan, and does not occur in the Flora of China[], it is quite possible that the reports more correctly refer to a different species[].

Common Name:

General Information

Rumex daiwoo is an erect perennial plant with stout stems growing from a large, fleshy underground root; it can grow around 80 - 100cm tall[, ].
The plant is harvested from the wild for local use as a food, medicine and source of materials.
The plant is sometimes cultivated in China for medicinal use[].

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

Range

E. Asia - Japan.

Habitat

Wet meadows in lowland all over Japan[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.90 m
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

Species in this genus generally succeed in a variety of soils, but they prefer deep fertile moderately heavy soils that are humus-rich, moisture-retentive and also well-drained, with a position in full-sun or part shade[].
Being wind -pollinated, Rumex species usually hybridize readily, especially with other members of the genus they are more closely related to[].

Edible Uses

Leaves - cooked[, ].

Seed - cooked. Used to make a gruel[, ].

Medicinal

The root is a cooling, sharp and bitter tasting herb with anticoagulant, antipruritic, antipyretic, diuretic and laxative properties. It is used to treat hepatitis, constipation and abdominal cramps[, ].
Applied externally, the root is used to treat all kinds of boils and abscesses, fungal infections[].

The root and rhizome was a historic medicine for the treatment of hepatitis and skin diseases[]. Modern pharmacological studies have shown that this plant has a broad spectrum of biological properties, including antimicrobial, haemostatic, hypoglycaemic, antiinflammatory and cytotoxic[].

Other Uses

Although no specific mention has been made for this species, dark green to brown and dark grey dyes can be obtained from the roots of many species in this genus, They do not need a mordant[].
There is a report that the plant is used to kill bugs, but no details are given[, ].

Propagation

Seed - sow spring in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer.
Division in spring.