thinleaf alder Betulaceae Alnus
incana ssp. tenuifolia (L.) Moench ssp. tenuifolia (Nutt.) Breitung symbol: ALINT
Leaf: Alternate, simple, oval, doubly serrated, 2 to 4 inches long, dull dark green above, paler with slight pubescence below, obviously thin.
Flower: Species is monoecious; in small clusters, preformed male catkins are 1/2 to 1 inch long, slender and green; females are much smaller, reddish green, open in early spring.
Fruit: Cone-like, 1/2 inch long, brown when ripe, each scale enclosing a very small winged seed, mature in late summer, and persistent.
Twig: Moderate, gray-brown to reddish brown, velvety, lighter lenticels, buds stalked, plump and reddish brown.
Bark: Smooth gray-green to reddish brown with numerous conspicuous horizontal white to light orange lenticels, becoming scaly on old trees.
Form: A thicket-forming suckering shrub or small tree that reaches 25 feet in height, and may reach 40 feet.
Looks like: speckled alder - hazel alder - Sitka alder - white alder
Additional Range Information: Alnus incana ssp. tenuifolia is native to North America. Range may be expanded by planting. See states reporting thinleaf alder.
External Links: USDAFS Additional Silvics - USDA Plants Database
All material © 2017 Virginia Tech Dept. of Forest Resources and Environmental Conservation; Photos and text by: John Seiler, Edward Jensen, Alex Niemiera, and John Peterson