Alnus alnobetula subsp. crispa, commonly known as American Green Alder, is a deciduous shrub native to cool temperate regions of Northern North America, including streambanks, wet woods, and moist slopes. It is also found in similar habitats in Northern Europe and Asia. This shrub typically grows at a moderate rate to a height and width of 6-20 feet (1.8-6 meters). American Green Alder has a multi-stemmed form with a rounded habit. The flowers are catkins, with the male catkins being yellow and pendulous and the female catkins green and smaller, blooming in early spring. The flowers are not particularly showy, but they are followed by small, woody cones that persist into winter and provide interest.

American Green Alder is valued for its ability to stabilize soil, especially in riparian zones, and for its nitrogen-fixing capabilities, which enrich the soil. It is often used for reclamation projects, erosion control, and as a component of naturalistic plantings. In cultivation, it requires full sun to part shade and thrives in medium to wet conditions, preferring clay, loam, or sandy soils with medium to slow drainage. It is relatively low-maintenance once established but may require additional water during dry periods.CC BY-SA 4.0