Both Rhus

Rhus aromatica vs Rhus trilobata

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

Confused 10x by our model Same genus Rhus Method published

Side by sidefigs. a and b

Rhus aromatica, photographed by Carol Ann McCormick
fig. a Carol Ann McCormick, CC BY 4.0

Rhus aromatica

fragrant sumac
Rhus trilobata, photographed by Amthinkia
fig. b Amthinkia, CC0 1.0

Rhus trilobata

Skunkbush Sumac

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Rhus aromatica Rhus trilobata 2 of 16 (13%)
Rhus trilobata Rhus aromatica 8 of 20 (40%)

The confusion is asymmetric, which is common and usually informative: it means one of these has a character the other lacks, rather than the two simply looking alike.

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

What actually separates themon the record

Family Both Anacardiaceae. The family does not separate them.
Genus Both Rhus. Congeners, which is why this is hard.
Flowering Peaks in May versus April. If the plant is in flower, timing helps. (n = 1,059 and 151.)

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