Skip Navigation

Species Search:
FieldGuidesthreatened and/or endangered search resultsthreatened and/or endangered

previous  | next

Mountain Alder Alnus incana (Alnus tenuifolia)


enlarge +

Mountain Alder, mature male and female fruit
credit: U.S. Forest Service

All Images


Get Our Newsletters


Advanced Search

Alternate name: Speckled Alder

Family: Betulaceae, Birch view all from this family

Description Alnus incana (Grey Alder or Speckled Alder) is a species of alder with a wide range across the cooler parts of the Northern Hemisphere.

It is a small to medium size tree 15-20 m tall with smooth grey bark even in old age, its life span being a maximum of 60-100 years. The leaves are matte green, ovoid, 5-11 cm long and 4-8 cm broad. The flowers are catkins, appearing early in spring before the leaves emerge, the male catkins pendulous and 5-10 cm long, the female catkins 1.5 cm long and one cm broad when mature in late autumn. The seeds are small, 1-2 mm long, and light brown with a narrow encircling wing. The Grey Alder has a shallow root system, and is marked not only by vigorous production of stump suckers, but also by root suckers, especially in the northern parts of its range. The wood resembles that of the black alder, but is somewhat paler and of little value.

Habitat Canyons & valleys, Mountains, Swamps (fresh & salt), Watersides (fresh).

Range Rocky Mountains, Alaska, Great Lakes, New England, Southwest, Plains, California, Southeast, Mid-Atlantic, Northwest, Western Canada.