Look for speckled alder along streams and rivers, and in marshy areas in the upper Midwest and eastern North America. It is a small tree with leaves that are both finely serrated and coarsely toothed. The bark is smooth and gray, and the female catkins are cone-like, becoming woody and remaining on the branches throughout the year. Speckled alder could be confused with smooth alder (with a range extending farther south, and leaves that are very finely serrated and not toothed), as well as green alder (with leaves that are shiny and sticky on their undersides). The western North American version of this tree species is thin-leaf alder, Alnus incana tenuifolia.

streamsides and marshy areas are favored locations for speckled alder

bark is brown when young . . .

. . . maturing to gray and smooth, with blisters

female catikins become woody and cone-like

leaves are both finely serrated and broadly toothed . . .

with shiny upper surfaces. . .

. . . and dull, paler under surfaces with rusty hairs along the veins

References: Harlow 1946, Peattie 1948, GN Jones 1971, Miller & Jaques 1978, Kricher & Morrison 1988, Preston 1989, RL Jones 2005, Mohlenbrock 2006, Kershaw 2007, Sibley 2009, Voss & Reznicek 2012, Mohlenbrock 2014, USDA 2022.

Kuo, Michael & Melissa Kuo (August, 2022). Alnus incana rugosa (speckled alder). Retrieved from the midwestnaturalist.com website: www.midwestnaturalist.com/alnus_incana_rugosa.html

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