Poaceae and Cyperaceae

Calamagrostis breviligulata vs Ficinia spiralis

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

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Calamagrostis breviligulata Ficinia spiralis 4 of 19 (21%)

The confusion runs one way only. The model mistakes Calamagrostis breviligulata for Ficinia spiralis, but not the reverse.

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

What actually separates themon the record

Family Poaceae versus Cyperaceae. Different families, which is a real separation.
Genus Calamagrostis versus Ficinia.
Flowering Peaks in August versus October. If the plant is in flower, timing helps. (n = 220 and 123.)

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