Both Acer

Acer glabrum vs Acer rubrum

These two are not on this page because a keyword tool suggested them. They are here because our own identification model genuinely mistook one for the other, on real photographs, 5 times. We publish the rate, and then we tell you what actually separates them.

Confused 5x by our model Same genus Acer Method published

Side by sidefigs. a and b

Acer glabrum, photographed by Jens-Christian Svenning
fig. a Jens-Christian Svenning, CC BY 4.0

Acer glabrum

Rocky Mountain maple
Acer rubrum, photographed by Jack Forrester
fig. b Jack Forrester, CC BY 4.0

Acer rubrum

red maple

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Acer glabrum Acer rubrum 5 of 20 (25%)

The confusion runs one way only. The model mistakes Acer glabrum for Acer rubrum, but not the reverse.

Measured on 38,299 openly licensed, research-grade photographs. Full method and dataset.

What actually separates themon the record

Family Both Sapindaceae. The family does not separate them.
Genus Both Acer. Congeners, which is why this is hard.
Flowering Peaks in May versus April. If the plant is in flower, timing helps. (n = 178 and 3,333.)

What we do not have yet: the diagnostic morphological character that a botanist would key on, from a source we can cite. We are not going to invent one. Until we have it, this page tells you the two are genuinely confusable, how often, and what the taxonomy and the flowering data do and do not settle.

Both recordsfull pages