Both Polystichum
Polystichum munitum vs Polystichum vestitum
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
Polystichum munitum
western sword fern
Polystichum vestitum
Prickly Shield Fern
How often our model gets it wrong measured, not estimated
| When the plant was | The model said | How often |
|---|---|---|
| Polystichum vestitum | Polystichum munitum | 5 of 17 (29%) |
Measured on 38,299 openly licensed, research-grade photographs. Full method and dataset.
What actually separates themon the record
| Family | Both Dryopteridaceae. The family does not separate them. |
|---|---|
| Genus | Both Polystichum. Congeners, which is why this is hard. |
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.