White Alder
Alnus rhombifolia
Family: Betulaceae
What it is like
Bloom Color: Yellow. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Oval, Pyramidal.
Alnus rhombifolia is a deciduous Tree growing to 12 m (39ft 4in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 7. It is in flower in March, and the seeds ripen from October to January. 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 tolerates strong winds but not maritime exposure.
Height (m): 12
Where it is found
Usually found in rocky or gravelly soils along the sides of streams, in canyon bottomlands and gulches, from near sea level to 2400 metres.
Western N. America - British Columbia to California.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Catkins - raw or cooked. A bitter flavour. Inner bark. No more information is given, but inner bark is often dried and can be used as a flavouring in soups or can be mixed with cereal flours when making bread etc.
Inner bark: the bark that is found just beneath the tough outer bark of trees and shrubs.
Medicine
Rating: 2
The bark is astringent, diaphoretic, emetic, haemostatic, stomachic and tonic. A decoction of the dried bark is used in the treatment of diarrhoea, haemorrhages in consumption, stomach aches and to facilitate child birth. Externally it can be used as a wash for babies with skin diseases, nappy rash etc. A poultice of the wood is applied to burns.
Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.
Birthing aid: Used in facilitating birth, but not just to cause uterine contrctions.
Diaphoretic: Induces perspiration.
Emetic: Induces vomiting.
Haemostatic: Controls internal bleeding.
Skin: Plants used in miscellaneous treatments for the skin.
Stomachic: Aids and improves the action of the stomach.
TB: Plants used in the treatment of tuberculosis
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating:
The bark and the strobils are a source of tannin. The roots have been used to make baskets. The inner bark can be dried, ground into a powder then mixed with flour and water for use as a dye. The colour is not specified. The fresh bark can be chewed and used as a red dye. Wood - light, soft, not strong, brittle, close and straight-grained, very durable in water. It is of limited value as a low-grade lumber, but is used principally for fuel.
Baby care: Various plants that can be used in place of items such as nappies.
Basketry: Plant used in making baskets and other items such as chairs. Includes plants that are only used as an ornamental addition.
Dye: Plants that provide dyes.
Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.
Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.
Wood: A list of the trees and shrubs that are noted for having useful wood.
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
Landscape Uses:Massing, Woodland garden. Prefers a heavy soil and a damp situation. Grows well in heavy clay soils. Tolerates very infertile sites. A fairly fast-growing but short-lived species, reaching its maximum size in 50 - 60 years. This species has a symbiotic relationship with certain soil micro-organisms, these form nodules on the roots of the plants and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby. Special Features:North American native, Wetlands plant, Inconspicuous flowers or blooms. In garden design, as well as the above-ground architecture of a plant, root structure considerations help in choosing plants that work together for their optimal soil requirements including nutrients and water. The root pattern is branching: a heart root, dividing from the crown into several primary roots going down and out .
Propagating it: Seed - best sown in a cold frame as soon as it is ripe and only just covered. Spring sown seed should also germinate successfully so long as it is not covered. The seed should germinate in the spring as the weather warms up. When large enough to handle, prick the seedlings out into individual pots. If growth is sufficient, it is possible to plant them out into their permanent positions in the summer, otherwise keep them in pots outdoors and plant them out in the spring. If you have sufficient quantity of seed, it can be sown thinly in an outdoor seed bed in the spring. The seedlings can either be planted out into their permanent positions in the autumn/winter, or they can be allowed to grow on in the seed bed for a further season before planting them. Cuttings of mature wood, taken as soon as the leaves fall in autumn, outdoors in sandy soil.
Best place to grow: Woodland Garden Canopy; Bog Garden;
Habit: Tree
Hardiness: 8-11
Growth: Fast
Soil: Medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist, wet
Things to keep in mind
The freshly harvested inner bark is emetic but is alright once it has been dried.