Both Rhus

Rhus glabra vs Rhus typhina

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

Confused 9x by our model Same genus Rhus Method published

Side by sidefigs. a and b

Rhus glabra, photographed by Joseph Aubert
fig. a Joseph Aubert, CC BY 4.0

Rhus glabra

smooth sumac
Rhus typhina, photographed by Michelle Norcéide
fig. b Michelle Norcéide, CC BY 4.0

Rhus typhina

staghorn sumac

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Rhus glabra Rhus typhina 6 of 20 (30%)
Rhus typhina Rhus glabra 3 of 20 (15%)

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 38,949 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 June versus June. Timing does not separate them. (n = 1,358 and 1,042.)

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