There has been considerable uncertainty amongst botanists as to the best way of treating the genus Toxicodendron, with some viewing it as a genus distinct from Rhus, whilst others see insufficient differences and lump the two genera under Rhus. Toxicodendron is treated here as distinct, with two of the major differences from a gardener’s viewpoint being that Toxicodendron has a toxic sap (not toxic in Rhus) and the fruits have a thick, waxy mesocarp.

Common Name:

General Information

Toxicodendron delavayi is a deciduous shrub usually growing 50 - 200cm tall[].
The plant is harvested from the wild in large quantities for its seed, which is the source of an oil used in cooking and making soap[].
The seeds of Toxicodendron delavayi are harvested in considerable quantities, and habitat declines are also extensive. However, most of this species' range is now contained within nature reserves and so the plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(1998)[].

Known Hazards

Species in the genus Toxicodendron are known to contain resinous phenolic compounds known as urushiols that can cause severe skin problems in humans. Direct contacr with the plant, exposure to smoke or fumes from a burning plant or even contact with pets, animals or cothing that have touched the plant can cause severe allergic dermatitis in some individuals. There is usually a latent period of about 12 - 24 hours from the moment of contact, this is followed by a reddening and severe blistering of the skin. Even plant specimens 100 or more years old have been known to cause problems[].
The plant does not cause skin problems with wildlife or livestock - the foliage and fruits are eaten by several other species of animals and birds - though some pets are sensitive to it[].

Botanical References

Range

E. Asia - southern China (Sichuan, Yunnan)

Habitat

Hill and mountain forests, thickets; at elevations from 1,100 - 2,500 metres[].

Properties

Conservation Status	Least Concern
Edibility Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	1.50 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Succeeds in a well-drained fertile soil in full sun[]. Plants do not require a rich soil[].
Plants have brittle branches and these can be broken off in strong winds[]. Plants are also susceptible to coral spot fungus[].

Edible Uses

The oil from the seeds is used in cooking[].

Medicinal

None known

Other Uses

The oil from the seeds is used in soap-making[]. The oblique fruits are around 6mm in diameter[].

Propagation

Seed - best sown in a cold frame as soon as it is ripe. Pre-soak the seed for 24 hours in hot water (starting at a temperature of 80 - 90c and allowing it to cool) prior to sowing in order to leach out any germination inhibitors[]. The stored seed also needs hot water treatment and can be sown in early spring in a cold frame[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, 10cm with a heel, mid summer in a frame[].
Root cuttings 4cm long taken in December and potted up vertically in a greenhouse. Good percentage[, ].
Suckers in late autumn to winter[].