Both Carex

Carex grayi vs Carex intumescens

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

Confused 3x by our model Same genus Carex Method published

Side by sidefigs. a and b

Carex grayi, photographed by Ryan Sorrells
fig. a Ryan Sorrells, CC BY 4.0

Carex grayi

Gray's sedge
Carex intumescens, photographed by John Baur
fig. b John Baur, CC BY 4.0

Carex intumescens

bladder sedge

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Carex grayi Carex intumescens 3 of 20 (15%)

The confusion runs one way only. The model mistakes Carex grayi for Carex intumescens, 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 Cyperaceae. The family does not separate them.
Genus Both Carex. Congeners, which is why this is hard.
Flowering Peaks in May versus May. Timing does not separate them. (n = 75 and 257.)

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