Both Cactaceae
Carnegiea gigantea vs Ferocactus wislizeni
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, 5 times. We publish the rate, and then we tell you what actually separates them.
Confused 5x by our model Method published
Side by sidefigs. a and b
Carnegiea gigantea
saguaro
Ferocactus wislizeni
fishhook barrel cactus
How often our model gets it wrong measured, not estimated
| When the plant was | The model said | How often |
|---|---|---|
| Ferocactus wislizeni | Carnegiea gigantea | 5 of 20 (25%) |
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 | Carnegiea versus Ferocactus. |
| Flowering | Peaks in May versus August. If the plant is in flower, timing helps. (n = 1,926 and 407.) |
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.