A long-lived, extremely cold hardy, and shade-tolerant deciduous small tree/large shrub. A. glabrum is NOT tolerant of heat and will scorch if exposed to dry, sunny, windy sites.
When found in dense stands individual trees grow spindly to 32 ft tall. If growing in the open, it tends to be a rounded, multi-stemmed shrub that maxes out at 6 feet tall.
Native from Alaska south into Western Canada, the Western and Southwest US, and east into the Rocky Mountain states and beyond into Nebraska and South Dakota. It thrives along streambanks, wet canyons, and moist sites in high mountains.
Minimum temperature: -20° F
First photo by: Walter Siegmund (talk) - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4566859
Second photo by: Walter Siegmund (talk) - Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1081110