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Cascara sagrada (Frangula purshiana) is a Pacific Northwest shrub or small tree whose bark became a widely used stimulant laxative. Older botanical literature often lists the name Rhamnus purshiana. Its history is significant, but stimulant-laxative herbs require much more caution than ordinary food herbs.
Materia Medica
- Accepted name: Frangula purshiana
- Older synonym: Rhamnus purshiana
- Family: Rhamnaceae
- Growth: deciduous shrub or small tree
- Native range: western North America
- Traditional part: bark, historically aged or cured before use
Actions & Energetics
Historical Western description: bitter, active bowel stimulant, formerly characterized as a cathartic or laxative. These terms describe traditional classification and action rather than a modern license to market a product.
Botanical Description
A deciduous Rhamnaceae shrub or small tree of the Pacific Northwest with alternate simple leaves, curved lateral veins, small greenish flowers, and darkening fruit. The bark of branches and trunks is the historic drug part, distinct from leaf, fruit and root.
Name Confusion & Look-Alikes
Rhamnus purshiana is an older pharmacy name for the accepted species Frangula purshiana. It is distinct from European alder buckthorn (Frangula alnus) and common buckthorn (Rhamnus cathartica), whose names and preparation histories are not interchangeable.