Rhus ambigua
a deciduous member of the Rhus genus in the family Anacardiaceae.
Taxonomy and growth
- Family
- Anacardiaceae
- Genus
- Rhus
- Foliage
- deciduous
- Fertility
- Self sterile, Bees
- Flower type
- dioecious
- Pollinators
- Bees
Uses
Toxicity
Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.
This section contains historical Plants For A Future notes marked noncommercial.
This plant contains toxic substances that can cause severe irritation to some people[7]. All parts of the plant contain resinous phenolic compounds known as urushiols. Direct contacr with the plant, exposure to smoke or fumes from a burning plant or even contact with pets or animals 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 can cause problems[4].
Material uses
This section contains historical Plants For A Future notes marked noncommercial.
The leaves are rich in tannin. They can be collected as they fall in the autumn and used as a brown dye or as a mordant. An oil is extracted from the seeds[5]. It attains a tallow-like consistency on standing and is used to make candles. These burn brilliantly, though they emit a pungent smoke[5]. A natural lacquer is obtained by tapping the stem[6][8].
- Product or use
- Dye
- Product or use
- Lacquer
- Product or use
- Mordant
- Product or use
- Oil
Ecology and functions
- Ecosystem niche
- Climber
Environment
- Range
- E. Asia - Japan.
- Habitat
- Mountainous woods all over Japan[7].
- Light
- full sun
- Shade tolerance
- light shade
- Water
- moderate
- Hardiness
- Zone 7+
- Soil textures
- sandy, loamy, clay
- Soil pH
- acid, neutral, alkaline
- Drainage
- well drained
- Tolerates Nutritionally Poor Soil
- No
- Drought
- intolerant
Propagation
This section contains historical Plants For A Future notes marked noncommercial.
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[3]. The stored seed also needs hot water treatment and can be sown in early spring in a cold frame[3]. 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, July/August in a frame[3]. Root cuttings 4cm long taken in December and potted up vertically in a greenhouse. Good percentage[9][3]. Suckers in late autumn to winter[3].
Cultivation
This section contains historical Plants For A Future notes marked noncommercial.
Succeeds in a well-drained fertile soil in full sun[2][3]. A woodland plant in its native habitat, it should also succeed in some shade[K]. The young growth in spring can be damaged by late frosts. Plants have brittle branches and these can be broken off in strong winds[3]. Plants are also susceptible to coral spot fungus[2]. Many of the species in this genus, including this one, are highly toxic and can also cause severe irritation to the skin of some people, whilst other species are not poisonous. It is relatively simple to distinguish which is which, the poisonous species have axillary panicles and smooth fruits whilst non-poisonous species have compound terminal panicles and fruits covered with acid crimson hairs[1][5]. The toxic species are sometimes separated into their own genus, Toxicodendron, by some botanists[3]. Plants in this genus are notably resistant to honey fungus[3]. Dioecious. Male and female plants must be grown if seed is required.
References
F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00
Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981-00-00
Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5
Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J Illustrated Flora of North Central Texas Botanical Research Institute, Texas. 1999-00-00 http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm
Grieve. A Modern Herbal. Penguin 1984-00-00 ISBN 0-14-046-440-9
Schery. R. W. Plants for Man.
Ohwi. G. Flora of Japan. (English translation) Smithsonian Institution 1965-00-00
Howes. F. N. Vegetable Gums and Resins. Faber
Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948-00-00