a widely distributed tree of the birch family, which has toothed leaves and bears male catkins and woody female cones 桤木,赤杨
Genus Alnus, family Betulaceae: many species, especially the common or European alder (A. glutinosa), common in damp ground and on riverbanks 桤属,桦木科: 多种,尤指普通(或欧洲)桤木(拉丁名 A. glutinosa),通常长在湿地和河岸
语源
Old English alor, aler, of Germanic origin; related to German Erle; forms spelled with d are recorded from the 14th cent