Alnus rhombifoliaNutt.

white alder

WFO wfo-0000947401 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Alnus rhombifolia, photographed by Michael Warner
fig. a Michael Warner, CC BY 4.0 / 2022-06-05 / obs. 203870250
Alnus rhombifolia, photographed by Mary K. Hanson
fig. b Mary K. Hanson, CC BY 4.0 / obs. 194043297
Alnus rhombifolia, photographed by Millie Basden
fig. c Millie Basden, CC BY 4.0 / obs. 192192140
Alnus rhombifolia, photographed by Tim Messick
fig. d Tim Messick, CC BY 4.0 / obs. 187599265
Alnus rhombifolia, photographed by Dan Horowitz
fig. e Dan Horowitz, CC0 1.0 / obs. 203749028
Alnus rhombifolia, photographed by paulexcoff
fig. f paulexcoff, CC BY-SA 4.0 / obs. 189367447
Alnus rhombifolia, photographed by velodrome
fig. g velodrome, CC BY 4.0 / obs. 195846052
Alnus rhombifolia, photographed by Dan Horowitz
fig. h Dan Horowitz, CC0 1.0 / obs. 182173807

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Confused withby our own model

These are not lookalikes we guessed at. Each one is a species our identification model genuinely mistook for this plant, and how many times. The error rate is published.

Flowering n = 85 observations

Peak flowering in Jan, from 85 community-annotated observations worldwide. This is a global aggregate, not a forecast for your garden: the same species flowers on different dates in different hemispheres, and citizen-science records cluster near cities, at weekends, and in spring. Where a species has fewer than 30 annotated records we do not draw this chart at all.

Also published as 5 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Alnus californica (Regel) H.J.P.Winkl.
  • Alnus glutinosa lus. californica Regel
  • Alnus rhombifolia var. bernardina Munz & I.M.Johnst.
  • Alnus rhombifolia var. ovalis H.J.P.Winkl.
  • Alnus rhombifolia var. typica Callier

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.

We publish what we can source and we say so when we cannot. This page has no care advice, no toxicity claim and no native range, because we do not yet have those from a source we can cite.