Noun: mountain alder
- Tree of western United States
"mountain alder grows along mountain streams in California";
- white alder, Alnus rhombifolia
- Small shrubby maple of eastern North America; scarlet in autumn
"The mountain alder's brilliant fall colours lit up the hillside";
- mountain maple, Acer spicatum
Derived forms: mountain alders
Type of: alder, alder tree, maple
Part of: Alnus, genus Alnus
Encyclopedia: Mountain alder