Common Name: Lilac Daphne

General Information

Daphne genkwa is a much-branched, deciduous shrub that can grow around 30 - 150cm tall[, ] tall.
The plant is harvested from the wild for local use as a medicine. It is commonly grown as an ornamental, valued especially for its flowering display.

Known Hazards

All parts of the plant are poisonous[]. Skin contact with the sap can cause dermatitis in some people[].

Botanical References

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Range

E. Asia - Japan, Korea, eastern and central China

Habitat

Margins of paddy fields, hillsides and valleys[, ]. Grassy hills and plains, limestone cliffs, on boulders, on conglomerate and in piles of stones removed from fields[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	1.50 m
Pollinators	Bees, Flies, Lepidoptera
Cultivation Status	Ornamental, Wild

Cultivation Details

Plants are hardy to about -20°c, but they are short-lived and difficult to grow in cultivation in Britain[, ]. This might be because our summers are not warm enough for the plants to develop properly[, ], they seem to be fully hardy after hot summers[].
There is some disagreement over whether this species needs an acid or alkaline soil. According to some reports it requires a lime-free porous soil and semi-shade[, ] whilst another report says that it is probably best in a deep rubbly well-drained soil in a warm corner and kept well watered in a dry growing season[]. Yet another report says that it grows best in a neutral to alkaline soil in sun or semi-shade[]. A good sandy loam suits most members of this genus[].
It can be tricky to get this plant to flower because the buds are formed in the autumn on wood of that year's growth and they may not survive our variable winters[, ].
Produces suckers when growing in its native habitat.
Plants are best grown on their own roots, grafted plants tend to be unsatisfactory.
Plants are resentful of root disturbance and should be planted into their permanent positions as soon as possible[].

Edible Uses

None known

Medicinal

This plant has a history of herbal use going back over 3,500 years[]. It is commonly used in Chinese herbalism, where it is considered to be one of the 50 fundamental herbs[].
The flower buds are a bitter acrid herb that is used to control coughs. The buds are anticoagulant, antiseptic, antitussive, antiviral, diuretic, purgative and stomachic[, , , , , ]. They are used internally in the treatment of bronchitis, constipation, oedema and skin diseases[]. The buds are also used as an abortifacient[].
They are applied externally in the treatment of frostbite[].
The buds are harvested and dried in the spring[] and are used after they have been stored for several years[].

The root is abortifacient, anticoagulant, diuretic, purgative and vesicant[].

Other Uses

An extract of the buds (?flower) is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].

In a trial, a methane extract of the flower buds at a concentration of 10,000ppm in distilled water reduced the egg hatching of root nematodes by 88% after 21 days compared with a control[].

Propagation

Seed - best sown in a greenhouse as soon as it is ripe with the pot sealed in a polythene bag to hold in the moisture. Remove this bag as soon as germination takes place[]. The seed usually germinates better if it is harvested 'green' (when it has fully developed but before it dries on the plant) and sown immediately. Germination should normally take place by spring, though it sometimes takes a further year. Stored seed is more problematic. It should be warm stratified for 8 - 12 weeks at 20°c followed by 12 - 14 weeks at 3°c. Germination may still take another 12 months or more at 15°c[]. Prick out the seedlings into individual pots as soon as they are large enough to handle. Grow the plants on in the greenhouse for their first winter and then plant out in spring after the last expected frosts.
Cuttings of half-ripe wood, mid summer in a frame.
Root cuttings, December in a greenhouse.