Red Alder, Oregon Alder

Alnus rubra

Physical Characteristics

Alnus rubra is a deciduous Tree growing to 20 m (65ft 7in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 6. It is in flower in March, and the seeds ripen from September to October. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Wind. It can fix Nitrogen. Suitable for: medium (loamy) and heavy (clay) soils and can grow in heavy clay and nutritionally poor soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil. The plant can tolerate maritime exposure.

Distribution

Western N. America - Alaska to California.

Habitats

Woodland Garden Canopy; Hedge; Bog Garden;

Edible Uses

Edible Parts: Flowers Inner bark Sap Edible Uses: Catkins - raw or cooked. They are rich in protein but have a bitter flavour and are not very palatable[172]. Inner bark - cooked, It must be dried since it is emetic when fresh[105, 161, 177]. No more details are given but inner bark is often dried, ground into a powder and then used as a thickening in soups etc or mixed with cereals when making bread[K]. Sap - raw[118]. Harvested in late winter, the flow is best on a warm, sunny day that follows a cold frosty night. A sweet flavour, it was often used to sweeten other foods[257]. Buds[105, 177]. No further information is given, does this refer to the flower buds or leaf buds?[K]

Medicinal Uses

Anodyne Appetizer Astringent Cathartic Cytostatic Eczema Febrifuge Skin Stomachic TB Tonic Red alder was widely employed medicinally by native North American Indians who mainly used the bark to treat a wide range of complaints[257]. The plant is little used in modern herbalism[K]. The bark is appetizer, astringent, cathartic, cytostatic, emetic, stomachic and tonic[61, 172, 257]. The bark contains salicin[226], which probably decomposes into salicylic acid (closely related to aspirin) in the human body[213]. This is used as an anodyne and febrifuge[226]. An infusion of the bark has been used in the treatment of many complaints such as headaches, rheumatic pains, internal injuries and diarrhoea[226, 257]. Externally, a poultice of the bark has been applied to eczema, sores and aches[257]. The sap is applied externally to cuts[257]. The catkins and young cones are astringent and have been chewed in the treatment of diarrhoea[257].

Known Hazards

The freshly harvested inner bark is emetic but is alright once it has been dried[172].