Both Brassicaceae

Mutarda nigra 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, 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

Mutarda nigra, photographed by David Lazarus
fig. a David Lazarus, CC0 1.0

Mutarda nigra

Black 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
Mutarda nigra Rapistrum rugosum 3 of 20 (15%)

The confusion runs one way only. The model mistakes Mutarda nigra for Rapistrum rugosum, but not the reverse.

Measured on 38,949 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 Mutarda versus Rapistrum.
Flowering Peaks in September versus July. If the plant is in flower, timing helps. (n = 178 and 580.)

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