Mountain Alder, Thinleaf alder

Alnus tenuifolia

Physical Characteristics

Alnus tenuifolia is a deciduous Tree growing to 9 m (29ft 6in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 2. It is in flower in March, and the seeds ripen in 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.

Distribution

Western N. America - Alaska to California and New Mexico.

Habitats

Woodland Garden Canopy; Secondary; Sunny Edge; Dappled Shade; Bog Garden;

Edible Uses

Edible Parts: Flowers Edible Uses: Catkins - raw or cooked. A bitter taste[172].

Medicinal Uses

Anodyne Astringent Emetic Febrifuge Haemostatic Stomachic Tonic The bark is astringent, emetic, haemostatic, stomachic and tonic[172]. The bark also 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]. The outer bark is astringent and is applied as a poultice to bleeding wounds, it also reduces swellings[226].

Known Hazards

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