- Red Alder
Red alder (scientific name Alnus rubra) is native to North America and is the largest alder species in the continent as well as among the largest worldwide. These trees are usually very tall, often growing up to a height of anything between 20 meters to 30 meters (66 feet to 98 feet). This species is called red alder because the scraped or bruised tree barks develop a bright rusty reddish hue.
Normally, the bark of red alder tree is spotted, smooth, has an ashy-grey hue and is usually covered with moss. These trees bear ovate leaves that measure anything between 7 cm and 15 cm (2.8 inches and 5.9 inches) in length.
The leaves have blunt, jagged edges with a noticeable point at their ends. The margin of the leaves is rolled backward (revolute), while the extreme edges are curled under. This is an indicative trait of red alder, which separates this species from the other alders. Before they shed in autumn, the color of the leaves changes to yellow.
The male flowers of red alder appear in early spring and hang down as red-hued catkins (spikes of unisexual, apetalous flowers) measuring about 10 cm to 15 cm (3.9 inches to 5.9 inches) long.
On the other hand, the female flowers are vertical catkins that turn into little, woody, apparently cone-like oval shaped dry fruits measuring about 2 cm to 3 cm (0.79 inch to 1.18 inches) in length. The seeds of red alder grow between the woody bracts of the superficial cones and they are dispersed during autumn as well as in winter.
Red alder grows very rapidly and is extremely resilient to wind. Therefore, these trees are ideal for use as quickly produced natural windbreakers. In addition, red alder trees have a widespread root system that makes them ideal for preventing soil erosion along river banks. One can also use these trees effectively to restore woodlands or any farmland that has been neglected for long.
They are also excellent for re-establishing difficult sites and similar purposes. Since these trees have a very fast growth rate, they are very effective for providing shelter conditions quickly, thereby allowing other more stable trees in woodlands to become established easily.
Moreover, the roots of red alder trees house beneficial bacteria that help in fixing atmospheric nitrogen, enabling the trees to thrive even in inferior quality soils, in addition to making additional nitrogen available to vegetations growing in the vicinity.
The red alder trees have a dense leaf canopy and, hence, when the trees shed all their leaves in autumn, they actually aid in building up the soil’s humus content. As the alder trees cannot compete with other trees in shaded forest conditions, they usually die when the other trees in the woodland become established.
The bark and strobils of red alder trees yield tannin, while the roots as well as the young shoots of the herb have been traditionally used for making baskets. The bark of this species also yields a dye whose color varies from red to brown. The timber of this tree is soft, fragile, not tough, and lightweight and is close as well as straight grained.
The wood of red alder trees is extremely hard-wearing in water. In fact, this is an excellent lumber tree and its wood is an excellent substitute as well as replication of mahogany. The wood of this tree is often used to make inexpensive furniture and similar objects. The wood of this tree is also used as a fuel and since it does not sparkle can be used safely in the open. In addition, this wood is also used to make superior quality charcoal.
There was a time when the native Indians of North America used the red alder extensively for therapeutic purposes. They used the bark of this tree for treating an assortment of health conditions. However, the red alder is seldom used in modern herbalism. The bark of this tree possesses astringent, appetizing, cytostatic, cathartic, stomachic, emetic and tonic properties.
Red alder bark encloses a natural element called salicin, which is presumed to break down to form salicylic acid inside the human body. Salicylic acid closely resembles aspirin chemically and is used in the form of an anodyne as well as febrifuge.
The bark of this tree is used to prepare an infusion, which is employed for treating several health problems including headaches, diarrhea, rheumatic pains as well as internal wounds. This infusion is also used externally and applied directly to sores, eczema and aches. Similarly, the sap of this tree is also applied topically to cuts. The catkins as well as the young cones of the herb possess astringent properties and earlier people chewed them for treating diarrhea.
Universally, it is accepted that the bark of red alder is an emetic and alterative. The bark is particularly prescribed for treating scrofula, various types of cutaneous diseases and secondary syphilis.
However, as far as treatment of secondary syphilis is concerned, this herb said to be inferior to other natural medicines like Stillingia or Rock Rose. (It is worth mentioning here that though there are various types of cutaneous diseases, some of them are yet to be classified).
Herbal practitioners use the active element of red alder (Alnus rubra) called alnuin, which is very effective for treating all types of dyspepsia caused by the sluggishness of the glands in the gastric system.
A decoction of the red alder bark yields a coffee colored dye, which the Native Indians of North America once used to color their fishing nets so that they are not very visible under the water.
Earlier, the bark of red alder was used by the native Indians for treating insect bites, poison oak and skin irritations. It is said that the Blackfeet Indians of North America prepared an infusion from the red alder bark and used it for treating tuberculosis and lymphatic problems. Clinical trials undertaken in recent times have confirmed that this herb encloses two natural compounds called lupeol and betulin – which have been found to be effective for treating various types of tumours.
The indigenous people of North America employed the bark of Alnus rubra for coloring their wool, wood, feathers, skin, human hair and basket materials. Subject to the technique employed, the colors yielded by red alder bark varied from brown to black to orange-red.
Some native people inhabiting the coastal areas used the inner cambium layer of the red alder tree for food. Since the red alder wood has a low pitch, it is excellent for smoking meat. In addition, people also used the wood of this tree to carve various items, for instance bowls.
The wood of red alder trees is used for multiple purposes, including making furniture, for flooring as well as firewood.
Catkins: The catkins of red alder trees are used for culinary purpose. They can be eaten raw or after cooking. The catkins of this species have a bitter flavour, but are rich in protein content. They are not too appetizing.
Inner bark: Even the inner bark of red alder trees is consumed after cooking. The inner bark is potently emetic and, hence, it is necessary to dry it before consumption. Usually, the inner bark of this tree is dried, pounded into a powdered form and subsequently consumed in the form of a thickening in soups and other similar foods. In addition, this powder is also blended with cereals for bread making.
Sap: the sap obtained from red alder trees is consumed raw. The sap is collected in the later part of winter. The sap secretion is best when the days are warm and sunny followed by a cold and frosty night. The sap has a sweet flavour and earlier it was frequently used for sweetening various foods.
Habitat and cultivation
Alnus rubra or red alder trees are unable to endure shade. These trees have a very rapid growth rate and usually shade out coniferous trees like the Douglas-fir. Red alder trees usually have a propensity to grow in places having rich soils, such as on the banks of streams and flood plains.
In its natural habitat, red alder is found growing with various other tree species that are indigenous to low elevation coast areas. This species is found growing among other species like grand fir, cedars, black cottonwood and Douglas-fir etc. Red alder has a tendency to co-exist with a dense stratum of herbs and shrubs, such as red elderberry, salmonberry and various different types of ferns.
Red alder is generally propagated from its seeds. Ideally, the seeds are sown immediately after they ripen in a cold frame and just covered lightly with soil. Seeds sown in spring usually germinate successfully, provided they are not covered. This is because the weather starts warming up in spring.
When the seedlings have grown sufficiently large, prick them out carefully and plant them into separate pots or containers. If the growth of the seedlings is satisfactory, it is preferable to plant the young plants in their permanent positions outdoors in summer. On the other hand, if the growth has not been sufficient, you need to continue growing them in their pots outdoors and plant them into their permanent positions some time in the next summer.
You may also plant the seedlings in their permanent positions outdoors in autumn or winter. Alternatively, you may let them grow in their seed bed itself for yet another season before planting them in their permanent positions.
Red alder trees may also be propagated from cuttings taken from mature wood. Ideally, the cuttings should be taken immediately when the trees shed their leaves in autumn. Sow the cuttings in a sandy soil outdoors.