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Toxic parts

There is the suggestion that this species could be mildly poisonous[1][2].

Edible uses


Fruit - raw or cooked[3][4][5][6]. A thin, rather juicy flesh[7]. It is sometimes eaten[8]. There is some debate as to whether the fruit is edible or slightly toxic[9]. The fruit is about 10mm in diameter[10] and contains 2 - 3 small seeds[11]. An extract of the bark, with the bitterness removed (by drying?) is a common flavouring for soft drinks, baked goods and ice cream[8].

Unknown part


Material uses

A green dye is obtained from the bark[12][4][6].

Plants are sometimes grown in America as an ornamental hedge[11].

Wood - light, soft, not strong. Used for making the handles of small tools[7][12].

Unknown part

Medicinal uses(Warning!)

Cascara sagrada is widely used as a gentle laxative that restores tone to the bowel muscles and thus makes repeated doses unnecessary[9][13]. It is often sold in chemists etc[9]. The bark is used, this is harvested on a commercial basis from wild trees and plantations in western N. America[9]. 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[14][15]. Three year old bark is considered to be the best age[16]. It is considered suitable for delicate and elderly persons and is very useful in cases of chronic constipation[16]. The bark also has tonic properties, promoting gastric digestion and appetite[17][16][18][19][20][21][14][22]. As well as its uses as a laxative, it is taken internally in the treatment of digestive complaints, haemorrhoids, liver problems and jaundice[23]. This remedy should be used with caution since in excess it causes vomiting and diarrhoea[23]. It should not be prescribed for pregnant or lactating women, or patients with intestinal obstruction[23]. 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[23].

Unknown part


Ecosystem niche/layer

Canopy or Secondary canopy

Ecological Functions



Nothing listed.


Nothing listed.


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[10]. 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[24]. Cuttings of mature wood of the current year's growth, autumn in a frame.

Layering in early spring[16].

Practical Plants is currently lacking information on propagation instructions of Rhamnus purshianus. Help us fill in the blanks! Edit this page to add your knowledge.


Succeeds in any reasonably good soil in sun or partial shade[18][23].

This species is hardy to at least -15°c[23]. Closely related to R. frangula[18]. This species is cultivated as a medicinal plant in N. America[20][25][26] and is also collected from the wild[23]. It is becoming rare in the wild because of over-collection[23]. The flowers are produced in small clusters on shoots of the current year's growth[7]. A good bee plant[21].

The species in this genus are notably resistant to honey fungus[10].


Problems, pests & diseases

Associations & Interactions

There are no interactions listed for Rhamnus purshianus. Do you know of an interaction that should be listed here? edit this page to add it.

Polycultures & Guilds

There are no polycultures listed which include Rhamnus purshianus.




None listed.


None listed.

Full Data

This table shows all the data stored for this plant.

Binomial name
Rhamnus purshianus
Imported References
Material uses & Functions
Edible uses
None listed.
Material uses
None listed.
Medicinal uses
None listed.
Functions & Nature
Provides forage for
Provides shelter for
Hardiness Zone
Heat Zone
full sun
light shade
Soil PH
Soil Texture
Soil Water Retention
Environmental Tolerances
    Native Climate Zones
    None listed.
    Adapted Climate Zones
    None listed.
    Native Geographical Range
    None listed.
    Native Environment
    None listed.
    Ecosystem Niche
    Root Zone Tendancy
    None listed.
    Deciduous or Evergreen
    Herbaceous or Woody
    Life Cycle
    Growth Rate
    Mature Size
    10 x 6 meters
    Flower Colour
    Flower Type


    1. ? Stary. F. Poisonous Plants. Hamlyn ISBN 0-600-35666-3 (1983-00-00)
    2. ? Frohne. D. and Pf?nder. J. A Colour Atlas of Poisonous Plants. Wolfe ISBN 0723408394 (1984-00-00)
    3. ? 3.03.1 Hedrick. U. P. Sturtevant's Edible Plants of the World. Dover Publications ISBN 0-486-20459-6 (1972-00-00)
    4. ? Gunther. E. Ethnobotany of Western Washington. University of Washington Press ISBN 0-295-95258-X (1981-00-00)
    5. ? 5.05.1 Yanovsky. E. Food Plants of the N. American Indians. Publication no. 237. U.S. Depf of Agriculture. ()
    6. ? Moerman. D. Native American Ethnobotany Timber Press. Oregon. ISBN 0-88192-453-9 (1998-00-00)
    7. ? Sargent. C. S. Manual of the Trees of N. America. Dover Publications Inc. New York. ISBN 0-486-20278-X (1965-00-00)
    8. ? Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications ISBN 0-9628087-0-9 (1990-00-00)
    9. ? Lauriault. J. Identification Guide to the Trees of Canada Fitzhenry and Whiteside, Ontario. ISBN 0889025649 (1989-00-00)
    10. ? Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press ISBN 0-333-47494-5 (1992-00-00)
    11. ? Elias. T. The Complete Trees of N. America. Field Guide and Natural History. Van Nostrand Reinhold Co. ISBN 0442238622 (1980-00-00)
    12. ? Turner. N. J. Plants in British Columbian Indian Technology. British Columbia Provincial Museum ISBN 0-7718-8117-7 (1979-00-00)
    13. ? 13.013.1 Phillips. R. & Foy. N. Herbs Pan Books Ltd. London. ISBN 0-330-30725-8 (1990-00-00)
    14. ? Saunders. C. F. Edible and Useful Wild Plants of the United States and Canada. Dover Publications ISBN 0-486-23310-3 (1976-00-00)
    15. ? 15.015.1 Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books ISBN 0-449-90589-6 (1980-00-00)
    16. ? Grieve. A Modern Herbal. Penguin ISBN 0-14-046-440-9 (1984-00-00)
    17. ? 17.017.1 F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press (1951-00-00)
    18. ? Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray (1981-00-00)
    19. ? 19.019.1 Lust. J. The Herb Book. Bantam books ISBN 0-553-23827-2 (1983-00-00)
    20. ? Schery. R. W. Plants for Man. ()
    21. ? Sweet. M. Common Edible and Useful Plants of the West. Naturegraph Co. ISBN 0-911010-54-8 (1962-00-00)
    22. ? 22.022.1 Mills. S. Y. The Dictionary of Modern Herbalism. ()
    23. ? Bown. D. Encyclopaedia of Herbs and their Uses. Dorling Kindersley, London. ISBN 0-7513-020-31 (1995-00-00)
    24. ? Dirr. M. A. and Heuser. M. W. The Reference Manual of Woody Plant Propagation. Athens Ga. Varsity Press ISBN 0942375009 (1987-00-00)
    25. ? 25.025.1 Hitchcock. C. L. Vascular Plants of the Pacific Northwest. University of Washington Press (1955-00-00)
    26. ? Usher. G. A Dictionary of Plants Used by Man. Constable ISBN 0094579202 (1974-00-00)