Both Cenchrus

Cenchrus ciliaris vs Cenchrus setaceus

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 Cenchrus Method published

Side by sidefigs. a and b

Cenchrus ciliaris, photographed by Ricus Nel
fig. a Ricus Nel, CC BY 4.0

Cenchrus ciliaris

buffelgrass
Cenchrus setaceus, photographed by Adam J. Searcy
fig. b Adam J. Searcy, CC BY 4.0

Cenchrus setaceus

Fountain Grass

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Cenchrus ciliaris Cenchrus setaceus 3 of 16 (19%)

The confusion runs one way only. The model mistakes Cenchrus ciliaris for Cenchrus setaceus, 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 Poaceae. The family does not separate them.
Genus Both Cenchrus. Congeners, which is why this is hard.
Flowering Peaks in March versus April. If the plant is in flower, timing helps. (n = 286 and 621.)

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