Etymology: Alnus: ancient Latin name derived from the Celtic, "growth along streams"
Plants: perennial tree/shrub to 30' tall with open, spreading branches; dark gray to reddish brown, smooth bark with whitish, prominent, horizontal lenticels; often in dense thickets
Leaves: leaf oval to elliptic, firm, edges usually coarsely double toothed, not noticeably resin-coated
Flowers: elliptical winter buds stalked and parallel to the twig; male catkin in 1 or more clusters 3/4"-2 3/4" long; blooms in early spring
Fruits: oval, stalked fruit clusters
Habitat: moist to wet; streambanks, lakeshores, bogs, swamps, swales and roadsides
Conservation Status: Native
Flora of North America: Flora of North America Floristic Rating: Coefficient of Conservatism = 4, Wetland Indicator = OBL USDA Plants Database: Federal Distribution and detailed information including photos University of Wisconsin - Green Bay: Trees: Photos, descriptions, information University of Wisconsin - Green Bay: Wetland Plants: Photos, descriptions, information USGS - Northern Prairie Wildlife Research Center: Wetland Plants and Plant Communities of Minnesota and Wisconsin Virginia Tech Dept. of Forestry, College of Natural Resources: detailed description and photographs