Alnus
Alnus  (nomen botanicum ab Philippo Miller statutum) est genus arborum et fruticum familiae Betulacearum. Species variae alnorum a 23 ad 40 numerantur.

Descriptio

Unica species est arborum cum foliis deciduis (praeter laricem), cuius flores feminei (amenta vel et iuli dicti) lignificant et iure nucamenta dici possunt.

Taxinomia
Tria subgenera habet:

Subgenus Alnus
 Alnus acuminata Kunth
 Alnus cordata  (Loisel.) Duby
 Alnus cremastogyne Burkill 
 Alnus firma Siebold & Zucc. 
 Alnus glutinosa  (L.) Gaertn.
 Alnus incana  (L.) Moench 
 Alnus incana subsp. rugosa  (Du Roi) Spreng. 
 Alnus hirsuta (Spach) Rupr.
 Alnus oblongifolia Torr. 
 Alnus tenuifolia Nutt. 
 Alnus japonica (Thunb.) Steud. 
 Alnus jorullensis Kunth 
 Alnus matsumurae Callier 
 Alnus nepalensis D.Don 
 Alnus orientalis Decne. 
 Alnus rhombifolia Nutt. 
 Alnus rubra Bong.
 Alnus serrulata  (Aiton) Willd.
 Alnus subcordata  C.A.Mey. 
 Alnus trabeculosa Hand.-Mazz. 

Subgenus Clethropsis
 Alnus formosana (Burkill) Makino 
 Alnus maritima (Marshall) Muhl. ex Nutt. 
 Alnus nitida (Spach) Endl.

Subgenus Alnobetula
 Alnus alnobetula (Ehrh.) K.Koch
 Alnus firma Siebold & Zucc. 
 Alnus mandshurica (Callier) Hand.-Mazz. 
 Alnus maximowiczii Callier 
 Alnus pendula  Matsum. 
 Alnus sieboldiana  Matsum. 

Aliae species
 Alnus djavanshirii H.Zare 
 Alnus dolichocarpa H.Zare, Amini & Assadi 
 Alnus fauriei H.Lév. & Vaniot 
 Alnus ferdinandi-coburgii C.K.Schneid. 
 Alnus hakkodensis Hayashi 
 Alnus henryi C.K.Schneid. 
 †Alnus heterodonta (Newberry) Meyer & Manchester 1987 
 Alnus lanata Duthie ex Bean 
 Alnus mairei H.Lév. 
 Alnus paniculata Nakai 
 Alnus serrulatoides Callier 
 Alnus vermicularis Nakai

Nexus externi

Arbores
Betulaceae
Taxa Miller