Both Brassicaceae

Hirschfeldia incana vs Rapistrum rugosum

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 Method published

Side by sidefigs. a and b

Hirschfeldia incana, photographed by Millie Basden
fig. a Millie Basden, CC BY 4.0

Hirschfeldia incana

Shortpod Mustard
Rapistrum rugosum, photographed by Annika Lindqvist
fig. b Annika Lindqvist, CC BY 4.0

Rapistrum rugosum

annual bastard cabbage

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Rapistrum rugosum Hirschfeldia incana 6 of 20 (30%)

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

What actually separates themon the record

Family Both Brassicaceae. The family does not separate them.
Genus Hirschfeldia versus Rapistrum.
Flowering Peaks in May versus April. If the plant is in flower, timing helps. (n = 2,910 and 1,396.)

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