Both Solanum

Solanum douglasii vs Solanum nigrum

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 Same genus Solanum Method published

Side by sidefigs. a and b

Solanum douglasii, photographed by Millie Basden
fig. a Millie Basden, CC BY 4.0

Solanum douglasii

greenspot nightshade
Solanum nigrum, photographed by Daniel Cahen
fig. b Daniel Cahen, CC BY 4.0

Solanum nigrum

black nightshade

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Solanum douglasii Solanum nigrum 3 of 19 (16%)

The confusion runs one way only. The model mistakes Solanum douglasii for Solanum nigrum, 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 Solanaceae. The family does not separate them.
Genus Both Solanum. Congeners, which is why this is hard.
Flowering Peaks in November versus October. If the plant is in flower, timing helps. (n = 685 and 3,370.)

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