Images of the Gray Alder (Alnus incana)

Gray Alder

Alnus incana

The bark on this tree varies in colors of green-gray, grayish brown or reddish-brown and is smooth on younger plants but with a more cracked appearance on older plants. Two native American sub-species occur: Alnus incana subsp. rugosa, Speckled Adler, found in the northern US and eastern Canada, and Alnus incana subsp. tenuifolia, Thinleaf Alder found in the western US and western Canada.

Habitat:Bottomlands and swamps.

Growth Habit:Up to 30 feet tall, this species may grow as a shrub or small tree with several crooked long trunks.

Presence in US:AK AZ CA CO CT IA ID IL IN MA MD ME MI MN MT ND NH NJ NM NV NY OH OR PA RI UT VA VT WA WI WV WY

Presence in Canada:AB BC LB MB NB NF NS NT ON PE QC SK YT

This project was supported in part by NSF Grant IIS-03-25867 (ITR: An Electronic Field Guide: Plant Exploration and Discovery in the 21st Century) and by the Washington Biologists' Field Club.

Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the official views, opinions, or policy of the National Science Foundation (NSF).