Every accepted species in the genus is listed. A name links to its page when we hold at least three commercially licensed photographs of it. Where we do not, the row shows how many we actually found, which is usually none.
| Species | Authority | Usable photographs | Page |
|---|---|---|---|
| Alnus glutinosa | (L.) Gaertn. | 3,057 | documented |
| Alnus incana | (L.) Moench | 1,581 | documented |
| Alnus rubra | Bong. | 1,020 | documented |
| Alnus alnobetula | (Ehrh.) K.Koch | 660 | documented |
| Alnus serrulata | (Aiton) Willd. | 474 | documented |
| Alnus rhombifolia | Nutt. | 403 | documented |
| Alnus acuminata | Kunth | 136 | documented |
| Alnus cordata | (Loisel.) Duby | 136 | documented |
| Alnus lusitanica | Vít, Douda & Mandák | 92 | documented |
| Alnus hirsuta | (Spach) Rupr. | 63 | documented |
| Alnus formosana | (Burkill) Makino | 30 | documented |
| Alnus nepalensis | D.Don | 28 | documented |
| Alnus oblongifolia | Torr. | 26 | documented |
| Alnus japonica | (Thunb.) Steud. | 12 | documented |
| Alnus jorullensis | Kunth | 8 | documented |
| Alnus maximowiczii | Callier | 8 | documented |
| Alnus sieboldiana | Matsum. | 8 | documented |
| Alnus orientalis | Decne. | 7 | documented |
| Alnus subcordata | C.A.Mey. | 6 | documented |
| Alnus maritima | (Marshall) Muhl. ex Nutt. | 4 | documented |
| Alnus firma | Siebold & Zucc. | 1 | below the evidence gate |
| Alnus × hanedae | Suyinata | 0 | below the evidence gate |
| Alnus × hosoii | Mizush. | 0 | below the evidence gate |
| Alnus × mayrii | Callier | 0 | below the evidence gate |
| Alnus × peculiaris | Hiyama | 0 | below the evidence gate |
| Alnus × suginoi | Sugim. | 0 | below the evidence gate |
| Alnus betulifolia | G.Y.Li, Z.H.Chen & D.D.Ma | 0 | below the evidence gate |
| Alnus cremastogyne | Burkill | 0 | below the evidence gate |
| Alnus djavanshirii | H.Zare | 0 | below the evidence gate |
| Alnus dolichocarpa | H.Zare, Amini & Assadi | 0 | below the evidence gate |
| Alnus elliptica | Req. | 0 | below the evidence gate |
| Alnus fallacina | Callier | 0 | below the evidence gate |
| Alnus fauriei | H.Lév. & Vaniot | 0 | below the evidence gate |
| Alnus ferdinandi-coburgii | C.K.Schneid. | 0 | below the evidence gate |
| Alnus glutipes | (Jarm. ex Czerpek) Vorosch. | 0 | below the evidence gate |
| Alnus hakkodensis | Hayashi | 0 | below the evidence gate |
| Alnus henryi | C.K.Schneid. | 0 | below the evidence gate |
| Alnus lanata | Duthie ex Bean | 0 | below the evidence gate |
| Alnus mairei | H.Lév. | 0 | below the evidence gate |
| Alnus mandshurica | (Callier) Hand.-Mazz. | 0 | below the evidence gate |
| Alnus matsumurae | Callier | 0 | below the evidence gate |
| Alnus nitida | (Spach) Endl. | 0 | below the evidence gate |
| Alnus paniculata | Nakai | 0 | below the evidence gate |
| Alnus pendula | Matsum. | 0 | below the evidence gate |
| Alnus pubescens | Tausch | 0 | below the evidence gate |
| Alnus rohlenae | Vít, Douda & Mandák | 0 | below the evidence gate |
| Alnus serrulatoides | Callier | 0 | below the evidence gate |
| Alnus trabeculosa | Hand.-Mazz. | 0 | below the evidence gate |
| Alnus vermicularis | Nakai | 0 | below the evidence gate |
This site is commercial, so it can only publish photographs licensed for commercial use. Roughly three quarters of the photographs on iNaturalist are CC BY-NC, which excludes them. A species needs at least three usable photographs before we will build it a page, because a page with one picture and no traits tells you nothing you could not get from a search result, and generating hundreds of thousands of those is precisely the practice that got the previous version of this site deleted.
So the species above without a link are not errors and they are not omissions. They are real, accepted plants that we cannot yet document to the standard we hold ourselves to, and the count in the photographs column is exactly how far short we fall.