Any of various deciduous shrubs or trees of the genus Alnus, native chiefly to northern temperate regions and having alternate, simple, toothed leaves and tiny fruits in woody, conelike catkins.
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- 桤木一种桤木属的落叶灌木或乔木,原主要生长于北温带地区,有互生的锯齿形单叶,在其木本的锥体柔荑花序中有微小的果实