Ruellia caroliniensis vs Ruellia strepens
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.
Side by sidefigs. a and b
Ruellia caroliniensis
Ruellia strepens
How often our model gets it wrong measured, not estimated
| When the plant was | The model said | How often |
|---|---|---|
| Ruellia caroliniensis | Ruellia strepens | 3 of 20 (15%) |
| Ruellia strepens | Ruellia caroliniensis | 2 of 20 (10%) |
The confusion is asymmetric, which is common and usually informative: it means one of these has a character the other lacks, rather than the two simply looking alike.
Measured on 38,949 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 February versus May. If the plant is in flower, timing helps. (n = 1,129 and 327.) |
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.