Japanese Plum

Prunus japonica nakai

Physical Characteristics

Prunus japonica nakai is an evergreen Shrub growing to 0.5 m (1ft 8in) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 4. It is in flower in May, and the seeds ripen from July to August. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

E. Asia - China, Korea, Manchuria.

Habitats

Woodland Garden Sunny Edge; Dappled Shade;

Edible Uses

Edible Parts: Fruit Seed Edible Uses: Fruit - raw or cooked. A sweet agreeable flavour, they make a good pie[183]. A very good size, about 50mm in diameter with one large seed[200]. Seed - raw or cooked. Do not eat the seed if it is too bitter - see the notes above on toxicity.

Medicinal Uses

Aperient Aphrodisiac Carminative Demulcent Deobstruent Diuretic Lenitive Ophthalmic The kernels are aperient, carminative, demulcent, deobstruent, diuretic, lenitive and ophthalmic[147, 176, 178, 218, 279]. Their use lowers the blood pressure[176]. A decoction is used in the treatment of sluggish colon, constipation, oedema and inadequate elimination of urine[147]. The pits of this sub-species are aphrodisiac for both sexes[218]. The root is used in the treatment of constipation, children's fever, pinworms and teeth ailments[218]. All members of the genus contain amygdalin and prunasin, substances which break down in water to form hydrocyanic acid (cyanide or prussic acid). In small amounts this exceedingly poisonous compound stimulates respiration, improves digestion and gives a sense of well-being[238].

Known Hazards

Although no specific mention has been seen for this species, it belongs to a genus where most, if not all members of the genus produce hydrogen cyanide, a poison that gives almonds their characteristic flavour. This toxin is found mainly in the leaves and seed and is readily detected by its bitter taste. It is usually present in too small a quantity to do any harm but any very bitter seed or fruit should not be eaten. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death.