sour dock
Rumex daiwoo

Family: Polygonaceae

What it is like

Rumex daiwoo is a PERENNIAL growing to 1 m (3ft 3in). The species is hermaphrodite (has both male and female organs) and is pollinated by Wind. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Height (m): 1

Where it is found

Wet meadows in lowland all over Japan.

E. Asia - Japan.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 1

Leaves - cooked. Seed - cooked. Used to make a gruel.

Seed: includes nuts, cereals, peas and beans.

Medicine

Rating: 2

The root is anticoagulant, antipruritic, antipyretic, diuretic, laxative.

Anticoagulant: Removes blood clots.

Antipruritic: Treats itching of the skin.

Antipyretic: Treats fevers. See Febrifuge.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Laxative: Stimulates bowel movements in a fairly gentle manner.

Other

Rating: 1

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.

Dye: Plants that provide dyes.

Insecticide: Kills insects.

How it is grown

We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it should succeed outdoors in many parts of this country. The following notes are based on the general needs of the genus. 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.

Propagating it: 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.

Best place to grow: Bog Garden;

Habit: Perennial

Hardiness:

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist, wet

Things to keep in mind

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.

Its other names

Local names

Synonyms

R. madaio. Makino.