Acer glabrumTorr.

Rocky Mountain maple

WFO wfo-0000514267 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Acer glabrum, photographed by Jens-Christian Svenning
fig. a Jens-Christian Svenning, CC BY 4.0 / 2022-06-06 / obs. 204030198
Acer glabrum, photographed by Shane Johnson
fig. b Shane Johnson, CC0 1.0 / obs. 204670729
Acer glabrum, photographed by Jens-Christian Svenning
fig. c Jens-Christian Svenning, CC BY 4.0 / obs. 203965292
Acer glabrum, photographed by Jens-Christian Svenning
fig. d Jens-Christian Svenning, CC BY 4.0 / obs. 204035432
Acer glabrum, photographed by Jens-Christian Svenning
fig. e Jens-Christian Svenning, CC BY 4.0 / obs. 203886205
Acer glabrum, photographed by Shane Johnson
fig. f Shane Johnson, CC0 1.0 / obs. 204635392
Acer glabrum, photographed by Shane Johnson
fig. g Shane Johnson, CC0 1.0 / obs. 204486844
Acer glabrum, photographed by Shane Johnson
fig. h Shane Johnson, CC0 1.0 / obs. 204433670

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 = 178 observations

Peak flowering in May, from 178 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 21 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.

  • Acer barbatum Hook.
  • Acer diffusum Greene
  • Acer douglasii Hook.
  • Acer glabrum f. bicolor Pax
  • Acer glabrum f. monophyllum Schwer.
  • Acer glabrum f. tripartitum (Nutt.) Schwer.
  • Acer glabrum f. trisectum Sarg.
  • Acer glabrum subsp. diffusum (Greene) A.E.Murray
  • Acer glabrum subsp. douglasii (Hook.) Wesm.
  • Acer glabrum subsp. neomexicanum (Greene) E.Murray
  • Acer glabrum subsp. neomexicanum (Greene) A.E.Murray
  • Acer glabrum subsp. siskiyouense A.E.Murray
  • Acer glabrum subsp. torreyi (Greene) A.E.Murray
  • Acer glabrum var. greenei A.C.Keller
  • Acer glabrum var. parvifolium A.E.Murray
  • Acer glabrum var. torreyi (Greene) Smiley
  • Acer glabrum var. tripartitum (Nutt.) Pax
  • Acer neomexicanum Greene
  • Acer subserratum Greene
  • Acer torreyi Greene
  • Acer tripartitum Nutt.

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.