Speckled alder

repared by Jennifer L. D’Appollonio, Assistant Scientist, University of Maine, Orono, ME 04469. Updated March 2018.

Scientific name: Alnus incana (L.) Moench

Common name(s): speckled alder, gray alder

Links: USDA PLANTS Profile, NPIN Profile, Go Botany

Images: (to see enlargements [PC]: click on image, then right click and choose “view image”)


– in New England, ssp. rugosa (Du Roi) Spreng.

Small shrub 5′ to 20′ tall or a tree up to 40′. Bark dark brown and speckled with white streaks, twigs smooth to somewhat hairy, reddish-brown with scattered white lenticels. Buds blunt tipped, reddish- brown and stalked with two scales. Egg-shaped, alternate leaves, dark green, hairless and wrinkled above, whitened, dull and somewhat hairy beneath. Margin double-toothed and undulating. Unisexual flowers; male catkin is 2″-4″ long and female catkin is 0.5″-0.75″ long. Nuts tiny and winged borne in a distinctive persistent cone-like structure. Prefers moist soils.

– may be confused with A. serrulata or A. viridis; see left sidebar on Go Botany webpage