Asteraceae and Poaceae

Achillea millefolium vs Anthoxanthum odoratum

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

Confused 3x by our model Method published

Side by sidefigs. a and b

Achillea millefolium, photographed by Lynn Harper
fig. a Lynn Harper, CC0 1.0

Achillea millefolium

common yarrow
Anthoxanthum odoratum, photographed by Derek Winterburn
fig. b Derek Winterburn, CC BY 4.0

Anthoxanthum odoratum

sweet vernal grass

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Anthoxanthum odoratum Achillea millefolium 3 of 20 (15%)

Measured on 38,299 openly licensed, research-grade photographs. Full method and dataset.

What actually separates themon the record

Family Asteraceae versus Poaceae. Different families, which is a real separation.
Genus Achillea versus Anthoxanthum.
Flowering Peaks in July versus May. If the plant is in flower, timing helps. (n = 22,608 and 1,299.)

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