Alnus rubra

Taxonomy and growth

Family

Betulaceae

Genus

Alnus

Life cycle

perennial

Foliage

deciduous

Woodiness

woody

Growth rate

vigorous

Height

20 (unit unspecified)

Flower type

monoecious

Uses

Edible uses

This section contains historical Plants For A Future notes marked noncommercial.

Catkins - raw or cooked. They are rich in protein but have a bitter flavour and are not very palatable^[8]. Inner bark - cooked, It must be dried since it is emetic when fresh^[3][6][9]. 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^[5]. 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^[14]. Buds^[3][9]. No further information is given, does this refer to the flower buds or leaf buds?[K]

Medicinal uses

Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

Red alder was widely employed medicinally by native North American Indians who mainly used the bark to treat a wide range of complaints^[14]. The plant is little used in modern herbalism[K]. The bark is appetizer, astringent, cathartic, cytostatic, emetic, stomachic and tonic^[18][8][14]. The bark contains salicin^[12], which probably decomposes into salicylic acid (closely related to aspirin) in the human body^[11]. This is used as an anodyne and febrifuge^[12]. An infusion of the bark has been used in the treatment of many complaints such as headaches, rheumatic pains, internal injuries and diarrhoea^[12][14]. Externally, a poultice of the bark has been applied to eczema, sores and aches^[14]. The sap is applied externally to cuts^[14]. The catkins and young cones are astringent and have been chewed in the treatment of diarrhoea^[14].

Material uses

This section contains historical Plants For A Future notes marked noncommercial.

A fast-growing and very wind resistant tree, it is an excellent plant for providing rapidly produced shelterbelts[K]. The trees extensive root system also makes it suitable for controlling erosion along the banks of rivers^[12]. This is an excellent pioneer species for re-establishing woodlands on disused farmland, difficult sites etc^[12]. Its fast rate of growth means that it quickly provides sheltered conditions to allow more permanent woodland trees to become established. In addition, bacteria on the roots fix atmospheric nitrogen - whilst this enables the tree to grow well in quite poor soils it also makes some of this nitrogen available to other plants growing nearby. Alder trees also have a heavy leaf canopy and when the leaves fall in the autumn they help to build up the humus content of the soil. Alder seedlings do not compete well in shady woodland conditions and so this species gradually dies out as the other trees become established[K]. Tannin is obtained from the bark and the strobils^[20]. Both the roots and the young shoots have been used in making baskets^[14]. A red to brown dye is obtained from the bark^[18][5][14]. Wood - soft, brittle, not strong, light, close and straight-grained, very durable in water^[20]. An important lumber tree, it makes a good imitation mahogany^[17][2] and is used for cheap furniture etc^{[16][18][20][7][13]}. A good fuel, it does not spark so can be used in the open^[17][5][8], it also makes a high grade charcoal^[2].

Ecology and functions

Ecosystem niche

Canopy

Environment

Range

Western N. America - Alaska to California.

Habitat

Moist rich soils in woods, usually below 600 metres and within 50 km of the coast^[17][20][13].

Light

full sun

Shade tolerance

light shade

Water

high

Hardiness

Zone 6+

Soil textures

loamy, clay, heavy clay

Soil pH

acid, neutral, alkaline

Tolerances

high wind, maritime exposure

Wind

Yes

Maritime

Yes

Pollution

No

Tolerates Nutritionally Poor Soil

No

Drought

intolerant

Propagation

This section contains historical Plants For A Future notes marked noncommercial.

Seed Requires Scarification

No

Seed Requires Smokification

No

Seed Requires Stratification

No

Cultivation

This section contains historical Plants For A Future notes marked noncommercial.

Prefers a heavy soil and a damp situation^[1][4]. Grows well in heavy clay soils^[4]. Tolerates very infertile sites^[10]. A very wind resistant tree with excellent establishment in severely exposed sites, it tolerates severe maritime exposure[75, K]. The red alder is a very fast growing tree, even when planted in severe exposure[75, 229, K], but it is short-lived, dying when 60 - 80 years old^[13]. Trees that are 5 years old from seed have reached 6 metres in height on a very exposed site in Cornwall, they are showing no signs of wind-shaping[K]. This is an important pioneer tree, quickly invading logged or burnt over sites, and providing ideal conditions for other trees to become established[229, K]. A very ornamental tree^[1]. 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^[10]. Red alder has been estimated to fix as much as 300 kg of nitrogen per hectare^[15].

Related plants

• Alnus cordataItalian Alder
• Alnus glutinosaAlder
• Alnus hirsuta
• Alnus incanaGrey Alder

References

1. F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 32202/01/01

   ↩1↩2

2. Haywood. V. H. Flowering Plants of the World. Oxford University Press ISBN 0-19-217674-9

   ↩1↩2

3. Tanaka. T. Tanaka's Cyclopaedia of Edible Plants of the World. Keigaku Publishing 32202/01/01

   ↩1↩2

4. Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 32202/01/01

   ↩1↩2

5. Gunther. E. Ethnobotany of Western Washington. University of Washington Press 32202/01/01 ISBN 0-295-95258-X

   ↩1↩2↩3

6. Yanovsky. E. Food Plants of the N. American Indians. Publication no. 237. U.S. Depf of Agriculture.

   ↩

7. Hill. A. F. Economic Botany. The Maple Press 32202/01/01

   ↩

8. Schofield. J. J. Discovering Wild Plants - Alaska, W. Canada and the Northwest.

   ↩1↩2↩3↩4

9. Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 32202/01/01 ISBN 3874292169

   ↩1↩2

10. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 32202/01/01 ISBN 0-333-47494-5

    ↩1↩2↩3

11. Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books 32202/01/01 ISBN 0-449-90589-6

    ↩

12. Lauriault. J. Identification Guide to the Trees of Canada Fitzhenry and Whiteside, Ontario. 32202/01/01 ISBN 0889025649

    ↩1↩2↩3↩4↩5

13. Elias. T. The Complete Trees of N. America. Field Guide and Natural History. Van Nostrand Reinhold Co. 32202/01/01 ISBN 0442238622

    ↩1↩2↩3

14. Moerman. D. Native American Ethnobotany Timber Press. Oregon. 32202/01/01 ISBN 0-88192-453-9

    ↩1↩2↩3↩4↩5↩6↩7↩8↩9

15. Duke. J. Handbook of Energy Crops - 32202/01/01

    ↩

16. Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 32202/01/01

    ↩

17. Hitchcock. C. L. Vascular Plants of the Pacific Northwest. University of Washington Press 32202/01/01

    ↩1↩2↩3

18. Usher. G. A Dictionary of Plants Used by Man. Constable 32202/01/01 ISBN 0094579202

    ↩1↩2↩3

19. Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 32202/01/01

    ↩

20. Sargent. C. S. Manual of the Trees of N. America. Dover Publications Inc. New York. 32202/01/01 ISBN 0-486-20278-X

    ↩1↩2↩3↩4