Family Code: BETULA Genus Code: ALNUS Genus CN: alder Genus Authority: Mill. Genus Summary: A genus of about 25-35 species, shrubs and trees, of subarctic to warm temperate regions of the Northern Hemisphere, and in montane situations south to n. South America. Genus References: Furlow in FNA (1997); Furlow (1990)=Z; Hardin (1971)=Y; Schrader & Graves (2002)=X; Banaev & Adel’shin (2009)=V; Chery (2015)=U; Chen & Li (2004); Navarro et al. (2003); Kubitzki in Kubitzki, Rohwer, & Bittrich (1993). Key based in part on Schrader & Graves (2002). Last Updated: 2019-11-29 Publish: 1