Rhus vernix
Poison Sumach
a perennial woody deciduous member of the Rhus genus in the family Anacardiaceae.
Taxonomy and growth
- Family
- Anacardiaceae
- Genus
- Rhus
- Life cycle
- perennial
- Foliage
- deciduous
- Woodiness
- woody
- Height
- 3 m
- 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 and skin contact with it can cause severe irritation to some people[2]. The sap is extremely poisonous[2]. The sap contains 3-N pentadecycatechnol. Many people are exceedingly sensitive to this, it causes a severe spreading dermatitis. The toxins only reach the skin if the plant tissues have been damaged, but even indirect contact can cause severe problems[6].
Medicinal uses
Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.
This section contains historical Plants For A Future notes marked noncommercial.
Poison sumach has occasionally been used medicinally, though it is an extremely poisonous plant and great caution should be exercised. Any herbal use should only be undertaken under the supervision of a qualified practitioner. See also the notes above on toxicity. The plant has been used in the treatment of fevers, ague, ulcerated bladder, asthma and wasting diseases[9]. The plant has been used as a wash to treat foul ulcers[9].
- Product or use
- Febrifuge
- Product or use
- Miscellany
- Product or use
- Skin
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[4]. An oil is extracted from the seeds[10]. It attains a tallow-like consistency on standing and is used to make candles. These burn brilliantly, though they emit a pungent smoke[10]. An indelible black ink can be made from the sap[7]. A varnish is obtained from the sap, it is black, lustrous and durable[5][13].The final product is toxic[7]. Wood - light, soft, coarse grained[13]. It weighs 27lb per cubic foot[8].
- Product or use
- Dye
- Product or use
- Ink
- Product or use
- Mordant
- Product or use
- Oil
- Product or use
- Varnish
- Product or use
- Wood
Environment
- Range
- Eastern N. America - Maine to Vermont and Ontario, south to Florida, Missouri and Louisiana.
- Light
- full sun
- Shade tolerance
- no shade
- Water
- high
- Hardiness
- Zone 3+
- 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[6]. The stored seed also needs hot water treatment and can be sown in early spring in a cold frame[6]. 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[6]. Root cuttings 4cm long taken in December and potted up vertically in a greenhouse. Good percentage[12][6]. Suckers in late autumn to winter[6].
Cultivation
This section contains historical Plants For A Future notes marked noncommercial.
Succeeds in a well-drained fertile soil in full sun[2][6]. Requires a moist soil[3]. The young growth in spring can be damaged by late frosts. Plants have brittle branches and these can be broken off in strong winds[6]. Plants are also susceptible to coral spot fungus[2]. Plants in this genus are notably resistant to honey fungus[6]. 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][10]. The toxic species are sometimes separated into their own genus, Toxicodendron, by some botanists[6]. 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
Holtom. J. and Hylton. W. Complete Guide to Herbs. Rodale Press 1979-00-00 ISBN 0-87857-262-7
Buchanan. R. A Weavers Garden.
Stary. F. Poisonous Plants. Hamlyn 1983-00-00 ISBN 0-600-35666-3
Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5
Lauriault. J. Identification Guide to the Trees of Canada Fitzhenry and Whiteside, Ontario. 1989-00-00 ISBN 0889025649
Britton. N. L. Brown. A. An Illustrated Flora of the Northern United States and Canada Dover Publications. New York. 1970-00-00 ISBN 0-486-22642-5
Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998-00-00 ISBN 0-88192-453-9
Grieve. A Modern Herbal. Penguin 1984-00-00 ISBN 0-14-046-440-9
Fernald. M. L. Gray's Manual of Botany. American Book Co. 1950-00-00
Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948-00-00
Sargent. C. S. Manual of the Trees of N. America. Dover Publications Inc. New York. 1965-00-00 ISBN 0-486-20278-X