Conyza canadensis
Canada Fleabane
an annual member of the Conyza genus in the family Compositae.
Taxonomy and growth
- Family
- Compositae
- Genus
- Conyza
- Life cycle
- annual
- Height
- 1 m
- Spread
- 0.5 m
- Fertility
- Bees, Flies
- Flower type
- hermaphrodite
- Pollinators
- Bees, Flies
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.
Skin contact with the plant can cause dermatitis in some people[11].
Edible uses
This section contains historical Plants For A Future notes marked noncommercial.
Young leaves and seedlings - cooked[2][4]. Boiled, cooked in rice or dried for later use[5]. A nutritional analysis of the leaves is available[10]. The source of an essential oil that is used commercially for flavouring sweets, condiments and soft drinks[5]. The fresh leaves contain 0.2 - 0.66% essential oil[10].
- Product or use
- Condiment
- Plant part
- Leaves
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.
In traditional North American herbal medicine, Canada fleabane was boiled to make steam for sweat lodges, taken as a snuff to stimulate sneezing during the course of a cold and burned to create a smoke that warded off insects[14]. Nowadays it is valued most for its astringency, being used in the treatment of gastro-intestinal problems such as diarrhoea and dysentery[14]. It is said to be a very effective treatment for bleeding haemorrhoids[14]. The whole plant is antirheumatic, astringent, balsamic, diuretic, emmenagogue, styptic, tonic and vermifuge[16][17][18][8][11]. It can be harvested at any time that it is in flower and is best used when fresh[16][7][12]. The dried herb should not be stored for more than a year[12]. The seeds can also be used[16]. An infusion of the plant has been used to treat diarrhoea and internal haemorrhages[9] or applied externally to treat gonorrhoea[9] and bleeding piles[17]. The leaves are experimentally hypoglycaemic[10]. The essential oil found in the leaves is used in the treatment of diarrhoea, dysentery and internal haemorrhages[16][7][10]. It is a uterine stimulant[9] and is also said to be valuable in the treatment of inflamed tonsils plus ulceration and inflammation of the throat[16]. A tea of the boiled roots is used to treat menstrual irregularities[9]. A homeopathic remedy is made from the plant[18]. It is used in the treatment of haemorrhoids and painful menstruation[18].
- Product or use
- Astringent
- Product or use
- Diuretic
- Product or use
- Emmenagogue
- Product or use
- Homeopathy
- Product or use
- Hypoglycaemic
- Product or use
- Styptic
- Product or use
- Tonic
- Product or use
- VD
- Product or use
- Vermifuge
Material uses
This section contains historical Plants For A Future notes marked noncommercial.
The plant contains small quantities of essential oil[17]. Since the plant is readily obtainable, extraction of the oil is feasible - it has a special quality that would make it suitable in the making of perfumes with unusual nuances[17][13].
- Product or use
- Essential
Environment
- Range
- N. America. Naturalized in Britain[3].
- Habitat
- Light soils on waste and cultivated land, also on walls, avoiding acid soils in Britain[3].
- Light
- full sun
- Shade tolerance
- light shade
- Water
- moderate
- Hardiness
- Zone 7+
- Soil textures
- sandy, loamy
- Soil pH
- neutral, alkaline
- Drainage
- well drained
- Tolerances
- drought
- Tolerates Nutritionally Poor Soil
- No
- Drought
- tolerant
Propagation
This section contains historical Plants For A Future notes marked noncommercial.
Seed - we have no information on this species but suggest sowing the seed in spring in situ. An autumn sowing in situ might also be worthwhile.
Cultivation
This section contains historical Plants For A Future notes marked noncommercial.
Prefers a well-drained light or medium neutral to alkaline soil in a sunny position, though it tolerates most conditions[12]. Originally from N. America, Canada fleabane has become naturalized in many areas of the world and is considered to be a nuisance weed in many areas[15]. The plant is very adaptable to differing conditions and can vary dramatically in height, from only a few centimetres in poor soils to as much as 3 metres tall in rich soils[9]. The plant is used commercially as a food flavouring[5]. A good bee plant[6] but unfortunately it also harbours various insect pests such as the tarnished plant bug[1].
References
F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00
Tanaka. T. Tanaka's Cyclopaedia of Edible Plants of the World. Keigaku Publishing 1976-00-00
Clapham, Tootin and Warburg. Flora of the British Isles. Cambridge University Press 1962-00-00
Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984-00-00 ISBN 3874292169
Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9
Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5
Coffey. T. The History and Folklore of North American Wild Flowers. Facts on File. 1993-00-00 ISBN 0-8160-2624-6
Lust. J. The Herb Book. Bantam books 1983-00-00 ISBN 0-553-23827-2
Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books 1980-00-00 ISBN 0-449-90589-6
Duke. J. A. and Ayensu. E. S. Medicinal Plants of China Reference Publications, Inc. 1985-00-00 ISBN 0-917256-20-4
Foster. S. & Duke. J. A. A Field Guide to Medicinal Plants. Eastern and Central N. America. Houghton Mifflin Co. 1990-00-00 ISBN 0395467225
Bown. D. Encyclopaedia of Herbs and their Uses. Dorling Kindersley, London. 1995-00-00 ISBN 0-7513-020-31
Chopra. R. N., Nayar. S. L. and Chopra. I. C. Glossary of Indian Medicinal Plants (Including the Supplement). Council of Scientific and Industrial Research, New Delhi. 1986-00-00
Chevallier. A. The Encyclopedia of Medicinal Plants Dorling Kindersley. London 1996-00-00 ISBN 9-780751-303148
Stuart. M. (Editor) The Encyclopedia of Herbs and Herbalism Orbis Publishing. London. 1979-00-00 ISBN 0-85613-067-2
Grieve. A Modern Herbal. Penguin 1984-00-00 ISBN 0-14-046-440-9
Chiej. R. Encyclopaedia of Medicinal Plants. MacDonald 1984-00-00 ISBN 0-356-10541-5
Launert. E. Edible and Medicinal Plants. Hamlyn 1981-00-00 ISBN 0-600-37216-2