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Gray, or Speckled, Alder is a shrub or small tree that grows across much of Canada and the northeastern United States, and southward in the Appalachian Mountains. In Maryland it is limited to the western, mountainous part of the state. It occurs along streams and in swamps.

Compare with Smooth Alder. Leaves of Gray Alder are egg-shaped and coarsely doubly toothed. Bark is dark gray, with prominent, pale, horizontal lenticels. Male and female catkins form during the summer and persist through the winter. The female catkins are small and drooping, in contrast to Smooth Alder’s more erect female catkins. In the spring, male catkins elongate and female catkins produce very small red flowers. The cone-like fruiting structures that develop after fertilization resemble conifer cones. They are clustered and persist until the following growing season.

Look along streams, swales, and in swamps in Maryland’s westernmost counties.

Like all alders, Gray Alder has a symbiotic relationship with a bacterium that fixes nitrogen in nodules on the roots. This nitrogen is then available to the plant nutritionally. In this respect, the alders resemble the legumes and some other plants that fix nitrogen.

Host plant for various moth species including Serviceberry Leafroller Moth (Gilligan, Wright, & Gibson, 2008).

The leaf beetle Calligrapha alni uses Gray Alder as a host plant.

Woolly Alder Aphids use Gray Alder as one of their two alternate host plants (the other host being Silver Maple).