Alder

| synonyms =

|''Duschekia'' |''Alnaster'' |''Clethropsis'' |''Semidopsis'' |''Alnobetula'' |''Cremastogyne'' }} }}

Alders are trees of the genus ''Alnus'' in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species extending into Central America, as well as the northern and southern Andes. Provided by Wikipedia