European Alder. Family Betulaceae. Drawing.
Britton, N.L., and A. Brown. 1913. <i>Illustrated flora of the northern states and Canada.</i> Vol. 1: 613. Courtesy of Kentucky Native Plant Society.
1913
<a rel="nofollow" class="external free" href="https://plants.usda.gov/java/profile?symbol=ALGL2&amp;photoID=alal7_001_avd.tif">http://plants.usda.gov/java/profile?symbol=ALGL2&amp;photoID=alal7_001_avd.tif</a>