Rumex japonicus — Edible Plant Database

What to Eat

Edible parts: Leaves, Seeds

Leaves can be cooked as a vegetable, added to soups, or dried for later use. The seed is cooked and used with rice or ground into a powder for making dumplings.

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.

Where to Find It

It is a temperate plant. In China it grows between sea level and 3,400 m above sea level. It grows in wetlands. In Sichuan.

Asia, China, Japan, Korea, Russia, Taiwan,

Countries: United Arab Emirates, Afghanistan, Armenia, Azerbaijan, Bangladesh, Bahrain, Brunei, Bhutan, China, Georgia, Indonesia, Israel, India, Iraq, Iran, Jordan, Japan, Kyrgyzstan, Cambodia, North Korea, South Korea, Kuwait, Kazakhstan, Laos, Lebanon, Sri Lanka, Myanmar, Mongolia, Maldives, Malaysia, Nepal, Oman, Philippines, Pakistan, Qatar, Russia, Saudi Arabia, Singapore, Syria, Thailand, Tajikistan, Timor-Leste, Turkmenistan, Turkey, Taiwan, Uzbekistan, Vietnam, Yemen

How to Identify

A perennial growing to 1 m, hermaphroditic and wind-pollinated. Flowers May to June with seeds ripening June to July. Tolerates light sandy, medium loamy, and heavy clay soils with good drainage. Suitable for mildly acidic to basic soil pH. Grows in semi-shade or full sun and prefers moist soil conditions.

How to Grow

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 most 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.

Propagation: Sow seed in spring in situ. Can also be propagated by division in spring.

Medicinal Uses

None known.

Other Uses

No dye data specific to this species has been recorded, but roots of many plants in this genus yield dark green to brown and dark grey dyes without the need for a mordant.

Wikipedia