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Red Alder (Alnus rubra)
Materia Medica
Family: Betulaceae
Botanical name: Alnus rubra Bong.
Common names: Red Alder, Pacific Alder, Oregon Alder
Parts used: Bark, catkins
Growth habit: Deciduous tree
Primary traditions: Pacific Northwest Indigenous medicine
Actions & Energetics
Indigenous Pacific Northwest records describe the bark as astringent, tonic, and alterative. Fresh bark can be emetic. The tree is valued for both medicine and dye.
Botanical Description
Alnus rubra is a fast-growing deciduous tree of the Pacific Northwest with smooth gray bark that becomes reddish when cut. Leaves are elliptic to ovate. It produces male and female catkins and woody cones. It is nitrogen-fixing and colonizes disturbed or wet sites. Distinct from European Black Alder.
Traditional Indications
Coast Salish, Kwakiutl, Pomo, and other Indigenous groups of the Pacific Northwest recorded bark decoctions or infusions for colds, diarrhea, headaches, rheumatism, and as a tonic. Externally, bark poultices or washes were applied to sores, eczema, and wounds. The inner bark was used as a red-orange dye for baskets and nets. Sap was applied to cuts.
Preparations & Dosage
Bark Decoction
Traditional Indigenous preparations use a decoction of the bark for internal or external use. Specific gram amounts vary by community and are not standardized in classical texts.
Poultice
Bark or leaves applied externally to skin conditions and sores.
Constituents
Bark contains salicin, tannins, diarylheptanoids (including oregonin), and flavonoids. Salicin is related to the chemistry of willow.
Modern Research
Laboratory studies have examined astringent and antimicrobial properties. Human clinical data remain limited. Ethnobotanical records form the primary documentation.
Adverse Effects
Fresh bark can act as an emetic. Ordinary traditional external or low-dose dried bark use is the more common pattern. Pollen may cause allergy.
Interactions & Contraindications
No clinically established major drug interactions are recorded for ordinary traditional use.
Pregnancy & Breastfeeding
Historical records are limited. Ordinary external use is the primary traditional application.
Habitat & Cultivation
- Native range: Pacific Northwest of North America
- Habitat: Moist woods, stream banks, floodplains, disturbed sites
- Cultivation: Planted for reforestation and nitrogen fixation
Harvesting & Drying
Bark is harvested from young branches and dried. Fresh material is noted as more emetic. The tree is abundant in its native range.
History, Folklore & Spiritual Use
Red alder is one of the most important trees in Pacific Northwest Indigenous traditions for medicine, dye, and woodworking. The reddish color of the cut bark gave it its name and dye use. It was used for smoking fish and for canoes. The tree remains ecologically and culturally significant in the region.
Materia Medica Summary
Red Alder (Alnus rubra) is a Pacific Northwest tree recorded in Indigenous traditions for bark use as a tonic, for colds, diarrhea, and externally for sores and skin. The bark yields a red-orange dye. Fresh bark can be emetic. It is distinct from European Black Alder and Alder Buckthorn.