White Ash (Fraxinus americana)
Winter twigs with bud and leaf scar- classic ‘happy smile’ scar.
Winter twigs with buds starting to break dormancy.
New growth twig with terminal bud and petioles. (photo credit: Robbin Moran)
Summer growth and bud. Photo credit: H. Schibli
Red Ash (Fraxinus pennsylvanica)
Branch showing terminal bud, leaf scars, terminal bud scale scars.
Twig showing terminal and lateral buds. (photo credit: D.L. Nickrent)
Terminal bud and petioles. (photo credit: P. B. Pelser)
Summer bud- note how pubescent new growth is. Photo credit: H.Schibli
Black Ash (Fraxinus nigra)
Space between terminal and lateral buds is a feature of F.nigra. Buds are dark brown to black. Photo credit: Steve Baskauf (Vanderbilt University).
European Ash (Fraxinus excelsior)
Summer terminal and lateral buds, petioles. European ash buds are inky black. Photo credit: Kevin C. Nixon
Winter terminal and lateral buds plus leaf scar. source
Summer bud. Photo credit: H. Schibli
Pumpkin Ash (Fraxinus profunda)
Winter twig including terminal bud. source.
Summer bud and leaves. Photo credit: H. Schibli
Blue Ash (Fraxinus quadrangulata)
Blue twigs are winged. source
Summer growth. Note twigs are ‘square’. Photo credit: H. Schibli
Great resources for ash identification:
http://tcf.bh.cornell.edu/index.html
Featured image link.
Emerald Ash Borer Guelph 
