Both Cupressaceae

Sequoia sempervirens vs Thuja plicata

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

Confused 4x by our model Method published

Side by sidefigs. a and b

Sequoia sempervirens, photographed by Drew Meyer
fig. a Drew Meyer, CC0 1.0

Sequoia sempervirens

coast redwood
Thuja plicata, photographed by Randal
fig. b Randal, CC0 1.0

Thuja plicata

western redcedar

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Thuja plicata Sequoia sempervirens 4 of 20 (20%)

Measured on 38,949 openly licensed, research-grade photographs. Full method and dataset.

What actually separates themon the record

Family Both Cupressaceae. The family does not separate them.
Genus Sequoia versus Thuja.

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