Both Sisyrinchium

Sisyrinchium angustifolium vs Sisyrinchium montanum

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, 4 times. We publish the rate, and then we tell you what actually separates them.

Confused 4x by our model Same genus Sisyrinchium Method published

Side by sidefigs. a and b

Sisyrinchium angustifolium, photographed by Jeff Clark
fig. a Jeff Clark, CC BY 4.0

Sisyrinchium angustifolium

narrow-leaved blue-eyed grass
Sisyrinchium montanum, photographed by Pierre Cartier
fig. b Pierre Cartier, CC0 1.0

Sisyrinchium montanum

strict blue-eyed grass

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Sisyrinchium montanum Sisyrinchium angustifolium 4 of 19 (21%)

Measured on 38,949 openly licensed, research-grade photographs. Full method and dataset.

What actually separates themon the record

Family Both Iridaceae. The family does not separate them.
Genus Both Sisyrinchium. Congeners, which is why this is hard.
Flowering Peaks in January versus May. If the plant is in flower, timing helps. (n = 508 and 753.)

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