A deciduous tree or shrub of the genus Alnus, comprising about 35 species native to north temperate zones and the Andes.
Alders form part of the birch family, along with hazels and hornbeams.
They are readily distinguished from the allied birches, Betula species, as they have small, woody cones which persist after the seeds have been dispersed. The common alder, A. glutinosa , of Eurasia and North Africa, is a plant of wet places in woods and on stream-sides, and its seeds attract siskins in winter. The wood of the North American red alder, A. rubra, has been used for furniture. The common alder has a soft, light timber used in the production of charcoal and plywood. The Macmillan Encyclopedia 2001 2.