Both Ruellia

Ruellia caroliniensis vs Ruellia humilis

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 Ruellia Method published

Side by sidefigs. a and b

Ruellia caroliniensis, photographed by Judith Bush
fig. a Judith Bush, CC BY-SA 4.0

Ruellia caroliniensis

Carolina ruellia
Ruellia humilis, photographed by saltyhiker
fig. b saltyhiker, CC BY 4.0

Ruellia humilis

hairy ruellia

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Ruellia caroliniensis Ruellia humilis 6 of 20 (30%)

The confusion runs one way only. The model mistakes Ruellia caroliniensis for Ruellia humilis, 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 Acanthaceae. The family does not separate them.
Genus Both Ruellia. Congeners, which is why this is hard.
Flowering Peaks in June versus July. If the plant is in flower, timing helps. (n = 1,667 and 1,122.)

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