Yunnan, Nepal, Bhutan, Myanmar, Thailand. Alnus oblongifolia Torr. – Arizona alder. Arizona, New Mexico, Sonora, Chihuahua Alnus orientalis Decne. – Oriental alder. Southern Turkey, northwest Syria, Cyprus, Lebanon, Iran Alnus rhombifolia Nutt. – white alder. California, Nevada, Oregon, Washington, Idaho, Montana Alnus rohlenae Vít, Douda, & Mandák - Western Balkans Alnus rubra Bong. – red alder. Alaska, Yukon, British Columbia, California, Oregon, Washington, Idaho, Montana. Alnus serrulata (Aiton) Willd. – hazel alder, tag alder or smooth alder. Eastern North America Alnus subcordata C.A.Mey. – Caucasian alder. Caucasus, Iran Alnus tenuifolia Nutt. – thinleaf or mountain alder. Northwestern North America Alnus trabeculosa Hand.-Mazz. – China, Japan Subgenus Clethropsis Trees or shrubs with stalked shoot buds, male and female catkins produced in autumn (fall) and expanding and pollinating then, three species: Alnus formosana (Burkill) Makino – Formosan alder. Taiwan Alnus maritima (Marshall) Muhl. ex Nutt. – seaside alder. United States (Georgia, Delaware, Maryland, Oklahoma). Alnus nitida (Spach) Endl. – Himalayan alder. Western Himalaya, Pakistan, India, Nepal. Subgenus Alnobetula Shrubs with shoot buds not stalked, male and female catkins produced in late spring (after leaves appear) and expanding and pollinating then, one to four species: Alnus alnobetula (Ehrh.) K.Koch subsp. alnobetula (Ehrh.) K.Koch subsp. crispa (Aiton) Raus subsp. fruticosa (Rupr.) Raus subsp. sinuata (Regel) Raus subsp. suaveolens (Req.) Lambinon & Kerguélen Alnus firma Siebold & Zucc. - Kyushu (Japan) Alnus mandshurica (Callier) Hand.-Mazz. – Russian Far East, northeastern China, Korea Alnus maximowiczii Callier – Japan, Korea, Russian Far East Alnus pendula Matsum. - Honshu and Hokkaido (Japan) Alnus sieboldiana Matsum. - Honshu, Shikoku, and Suwanose-jima (Japan) Not assigned to a subgenus Alnus fauriei H.Lév. & Vaniot – Honshu Island in Japan Alnus ferdinandi-coburgii C.K.Schneid. – southern China Alnus glutipes (Jarm. ex Czerpek) Vorosch. Alnus hakkodensis Hayashi – Honshu Island in Japan Alnus henryi C.K.Schneid. – Taiwan Alnus lanata Duthie ex Bean – Sichuan Province in China Alnus mairei H.Lév. – Yunnan Province in China Alnus paniculata Nakai – Korea Alnus serrulatoides Callier – Japan Alnus vermicularis Nakai – Korea Species names with uncertain taxonomic status The status of the following species is unresolved: Alnus balatonialis Borbás Alnus cuneata Geyer ex Walp. Alnus dimitrovii Jordanov & Kitanov Alnus djavanshirii H.Zare – Iran Alnus dolichocarpa H.Zare, Amini & Assadi – Iran Alnus figerti Callier Alnus frangula L. ex Huth Alnus gigantea Nakai Alnus glandulosa Sarg. Alnus henedae Sugim. Alnus hybrida Rchb. Alnus laciniata Ehrh. Alnus