Alnus Rubra, North America
Alnus rubra, red alder is a species of deciduous tree in the family Betulaceae. She is from the west coast of North America. Its name comes from the red color that can take its bark once slotted.
The extended area of the species extends from southwestern Alaska to central California. In general, it does not withdraw more than 200 km from the Pacific coast, with the exception of Washington state, since the species extending into Idaho.
With heights between 20 and 35 meters, it is the species of alder greatest. Its bark is gray and red once slotted. The leaves are oval (7 to 15 cm) and green colors. In autumn the leaf color turns yellow. The male inflorescence leaves reddish catkins hang from 10 to 15 cm long in spring. The female part is smaller and reveals pseudo-cones lignified 2 to 3 cm long. The seeds grow within the pseudo-cone before being released in the fall.
To the north, red alders grow everywhere, in all wet areas. To the south, they are limited to areas along rivers and swamps. It is found along the Douglas fir (Pseudotsuga menziesii) of western hemlock, fir Vancouver (Abies grandis), the giant California Cedar (Thuja plicata) of Sitka spruce (Picea sitchensis) and big leaf maple (Acer macrophyllum).
In the south it is replaced by a white alder, Alnus rhombifolia and mountainous areas by green alder, Alnus viridis or mountain alder Alnus incana. In wetlands, this is one of the first trees to colonize open areas. It improves soil quality (nitrogen fixation and nitrate production) and then allows other species to take place. The fruits of alder are very important to feed the local wildlife. Beavers eat the bark.
Natives used the bark of red alder to treat irritation caused by insects or plants toxic to touch. The Blackfoot used its bark to make tea to cure lymphatic disorders and tuberculosis. The shaft contains betulin and lupeol have a positive effect against tumors.
This is an important tree for the forest because its rapid growth can stabilize the land where trees have been removed. Its leaves improve soil quality. The wood is not durable or quality but it is still used for its ease of work.
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