Both Opuntia

Opuntia basilaris vs Opuntia microdasys

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

Confused 6x by our model Same genus Opuntia Method published

Side by sidefigs. a and b

Opuntia basilaris, photographed by velodrome
fig. a velodrome, CC BY 4.0

Opuntia basilaris

Beavertail Pricklypear
Opuntia microdasys, photographed by Marc Whitaker
fig. b Marc Whitaker, CC BY 4.0

Opuntia microdasys

Bunny Ears Cactus

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Opuntia microdasys Opuntia basilaris 6 of 19 (32%)

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

What actually separates themon the record

Family Both Cactaceae. The family does not separate them.
Genus Both Opuntia. Congeners, which is why this is hard.
Flowering Peaks in April versus May. If the plant is in flower, timing helps. (n = 3,813 and 143.)

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