Ranunculus japonicus

Thunb.

Crowfoot

Ranunculaceae Edible: Leaves Potential hazards — see below 880 iNaturalist observations

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Summary

A low-growing perennial reaching only 10cm tall with a spread of 30cm, flowering from May to July. Hermaphroditic flowers are pollinated by insects. Tolerates light sandy, medium loamy, and heavy clay soils with mildly acidic to basic pH. Grows in semi-shaded woodland or full sun, preferring moist soil conditions.

Description

A herb. It keeps growing from year to year. It has short rhizomes. The stems are 12-65 cm long. There are 3-6 leaves at the base. The leaves have 3 parts. They are heart shaped and 1-7 cm long by 2-10 cm wide. There are unequal teeth along the edge. The leaves on the stem are smaller. The flowers are 1.4-2.4 cm across.

Edible Uses

Leaves are edible when cooked. They contain a low level of toxicity, but not enough to be harmful.

Medicinal Uses

The plant is decongestant and vermicidal, and is used in the treatment of malaria. It also contains antitumour compounds.

Known Hazards

The leaves are poisonous. The toxicity is of a low measure and the toxins can be destroyed by heat or by drying[4, 10, 13, 19, 62, 65]. Many if not all plants in this genus also have a strongly acrid juice that can cause blistering to the skin.

Distribution

It is a tropical plant. In China it grows between 100-3,500 m above sea level.

Where It Grows

Asia, China, Indochina, Japan, Korea, Laos, Mongolia, Russia, SE Asia,

Cultivation

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 the country. It is clsely related to R. acris. The following notes are based on the general needs of the genus. Prefers a moist loamy soil. A greedy plant, inhibiting the growth of nearby plants, especially legumes.

Propagation

Sow seed in spring in a cold frame. Prick seedlings out into individual pots once large enough to handle, and plant out during summer. Can also be propagated by division in spring.