Both Rosa

Rosa californica vs Rosa woodsii

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, 7 times. We publish the rate, and then we tell you what actually separates them.

Confused 7x by our model Same genus Rosa Method published

Side by sidefigs. a and b

Rosa californica, photographed by George Williams
fig. a George Williams, CC BY 4.0

Rosa californica

California Wild Rose
Rosa woodsii, photographed by mark-groeneveld
fig. b mark-groeneveld, CC BY 4.0

Rosa woodsii

Woods' rose

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Rosa woodsii Rosa californica 7 of 20 (35%)

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

What actually separates themon the record

Family Both Rosaceae. The family does not separate them.
Genus Both Rosa. Congeners, which is why this is hard.
Flowering Peaks in June versus June. Timing does not separate them. (n = 3,545 and 1,349.)

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