Rhamnus purshianus
| Rhamnus purshianus | |
| Light: |   |
| Moisture: |  |
| Hardiness: | 7 |
| Soil pH: | 5.6-8.4 |
| Evergreen | |
| Height: | 33' |
| Width: | 20' |
| Blooms: | Late Spring-Early Summer |
| Native to: | |
| Shelter | |
| Edible Rating: |  |
| Medicinal Rating: |  |
| Tea: | Yes |
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Rhamnus purshianus (common name: cascara sagrada)
Propagation: Seed - best sown in the autumn in a cold frame. Stored seed will require 1 - 2 months cold stratification at about 5° and should be sown as early in the year as possible in a cold frame or outdoor seedbed[1]. Prick out the seedlings into individual pots when they are large enough to handle, and grow them on in the greenhouse or cold frame for their first winter. Plant them out in late spring or early summer of the following year.
Cuttings of half-ripe wood, July/August in a frame[2].
Cuttings of mature wood of the current year's growth, autumn in a frame.
Layering in early spring[3].
Cultivation: Succeeds in any reasonably good soil in sun or partial shade[4][5].
This species is hardy to at least -15°c[5].
Closely related to R. frangula[4].
This species is cultivated as a medicinal plant in N. America[6][7][8] and is also collected from the wild[5]. It is becoming rare in the wild because of over-collection[5].
The flowers are produced in small clusters on shoots of the current year's growth[9].
A good bee plant[10].
The species in this genus are notably resistant to honey fungus[1].
Range: Western N. America - British Columbia to California.
Habitat: Rich bottom lands and sides of canyons, usually in coniferous forests[7][9].
Edibility: Fruit - raw or cooked[11][12][13][14]. A thin, rather juicy flesh[9]. It is sometimes eaten[15]. There is some debate as to whether the fruit is edible or slightly toxic[16]. The fruit is about 10mm in diameter[1] and contains 2 - 3 small seeds[17].
An extract of the bark, with the bitterness removed (by drying?) is a common flavouring for soft drinks, baked goods and ice cream[15].
Medicinal: Cascara sagrada is widely used as a gentle laxative that restores tone to the bowel muscles and thus makes repeated doses unnecessary[16][18]. It is often sold in chemists etc[16]. The bark is used, this is harvested on a commercial basis from wild trees and plantations in western N. America[16]. It should be harvested in the autumn or spring at least 12 months before it is used medicinally, in order to allow the more violent purgative effect to be mollified with age[19][20]. Three year old bark is considered to be the best age[3]. It is considered suitable for delicate and elderly persons and is very useful in cases of chronic constipation[3].
The bark also has tonic properties, promoting gastric digestion and appetite[21][3][4][22][6][10][19][23]. As well as its uses as a laxative, it is taken internally in the treatment of digestive complaints, haemorrhoids, liver problems and jaundice[5]. This remedy should be used with caution since in excess it causes vomiting and diarrhoea[5]. It should not be prescribed for pregnant or lactating women, or patients with intestinal obstruction[5]. An infusion of the bark is sometimes painted over finger nails in the hope that the bitter taste will deter the person from biting their nails[5].
Usage: A green dye is obtained from the bark[24][12][14].
Plants are sometimes grown in America as an ornamental hedge[17].
Wood - light, soft, not strong. Used for making the handles of small tools[9][24].
Pollinators: Insects
Soil: Can grow in light, medium, and heavy soils.
In Leaf: Evergreen
Seed Ripens: Mid Fall
Flower Type: Hermaphrodite
Known Hazards: There is the suggestion that this species could be mildly poisonous[25][26].
Also Known As: Frangula purshiana. (DC.)Cooper.
Links
References
- ↑ 1.0 1.1 1.2 Huxley, Anthony. The New Royal Horticultural Society Dictionary of Gardening. MacMillan Press, 1992.
- ↑ Dirr, Michael and Charles Heuser. The Reference Manual of Woody Plant Propagation. Athens Ga. Varsity Press, 1987.
- ↑ 3.0 3.1 3.2 3.3 Grieve, Margaret. A Modern Herbal. Penguin, 1984.
- ↑ 4.0 4.1 4.2 Bean, William. Trees and Shrubs Hardy in Great Britain. Murray, 1981.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Bown, Deni. Royal Horticultural Society Encyclopaedia of Herbs and Their Uses. Dorling Kindersley, 1995.
- ↑ 6.0 6.1 Schery. Robert. Plants for Man. Prentice Hall, 1972.
- ↑ 7.0 7.1 Hitchcock, Leo. Vascular Plants of the Pacific Northwest. University of Washington Press, 1955.
- ↑ Usher, George. A Dictionary of Plants Used by Man. Constable, 1974.
- ↑ 9.0 9.1 9.2 9.3 Sargent, Charles. Manual of the Trees of North America. Dover, 1965.
- ↑ 10.0 10.1 Sweet, Muriel. Common Edible and Useful Plants of the West. Naturegraph Co, 1962.
- ↑ Hedrick, Ulysses. Sturtevant's Edible Plants of the World. Dover Publications, 1972.
- ↑ 12.0 12.1 Gunther, Erna. Ethnobotany of Western Washington. University of Washington Press, 1981.
- ↑ Yanovsky, Elias. Food Plants of the North American Indians Publication 237. US Department of Agriculture.
- ↑ 14.0 14.1 Moerman, Daniel. Native American Ethnobotany. Timber Press, 1998.
- ↑ 15.0 15.1 Facciola, Stephen. Cornucopia - A Source Book of Edible Plants. Kampong Publications, 1990.
- ↑ 16.0 16.1 16.2 16.3 Lauriault, Jean. Identification Guide to the Trees of Canada. Fitzhenry and Whiteside, 1989.
- ↑ 17.0 17.1 Elias, Thomas. The Complete Trees of North America. Van Nostrand Reinhold, 1980.
- ↑ Phillips, Roger. Herbs. Pan Books, 1990.
- ↑ 19.0 19.1 Saunders, Charles. Edible and Useful Wild Plants of the United States and Canada. Dover Publications, 1976.
- ↑ Weiner, Michael. Earth Medicine, Earth Food. Ballantine Books, 1980.
- ↑ Chittendon, Fred. RHS Dictionary of Plants. Oxford University Press, 1951.
- ↑ Lust, John. The Herb Book. Bantam Books, 1983.
- ↑ Mills, Simon. The Dictionary of Modern Herbalism.
- ↑ 24.0 24.1 Turner, Nancy. Plants in British Columbian Indian Technology. British Columbia Provincial Museum, 1979.
- ↑ Stary, Frantisek. Poisonous Plants. Hamlyn, 1983.
- ↑ Frohne, Dietrich and Hans Pfänder. J. A Colour Atlas of Poisonous Plants. Timber Press, 1984.