Both Dudleya

Dudleya cymosa vs Dudleya lanceolata

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 Same genus Dudleya Method published

Side by sidefigs. a and b

Dudleya cymosa, photographed by Arvel Hernandez
fig. a Arvel Hernandez, CC BY 4.0

Dudleya cymosa

Canyon liveforever
Dudleya lanceolata, photographed by velodrome
fig. b velodrome, CC BY 4.0

Dudleya lanceolata

lanceleaf liveforever

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Dudleya cymosa Dudleya lanceolata 5 of 18 (28%)

The confusion runs one way only. The model mistakes Dudleya cymosa for Dudleya lanceolata, 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 Crassulaceae. The family does not separate them.
Genus Both Dudleya. Congeners, which is why this is hard.
Flowering Peaks in May versus May. Timing does not separate them. (n = 681 and 385.)

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