Asparagaceae and Cactaceae

Hesperoyucca whipplei vs Opuntia littoralis

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 Method published

Side by sidefigs. a and b

Hesperoyucca whipplei, photographed by Amthinkia
fig. a Amthinkia, CC0 1.0

Hesperoyucca whipplei

chaparral yucca
Opuntia littoralis, photographed by Jim Riley
fig. b Jim Riley, CC0 1.0

Opuntia littoralis

Coastal Pricklypear

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Opuntia littoralis Hesperoyucca whipplei 3 of 16 (19%)

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

What actually separates themon the record

Family Asparagaceae versus Cactaceae. Different families, which is a real separation.
Genus Hesperoyucca versus Opuntia.
Flowering Peaks in May versus June. If the plant is in flower, timing helps. (n = 4,530 and 854.)

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