Both Brassicaceae

Lepidium virginicum vs Thlaspi arvense

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

Lepidium virginicum, photographed by Daniel Cahen
fig. a Daniel Cahen, CC BY 4.0

Lepidium virginicum

Virginia pepperweed
Thlaspi arvense, photographed by cgmayers
fig. b cgmayers, CC0 1.0

Thlaspi arvense

field penny-cress

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Thlaspi arvense Lepidium virginicum 3 of 20 (15%)

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 Lepidium versus Thlaspi.
Flowering Peaks in May versus May. Timing does not separate them. (n = 1,406 and 2,914.)

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