Both Tiarella

Tiarella cordifolia vs Tiarella trifoliata

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

Confused 4x by our model Same genus Tiarella Method published

Side by sidefigs. a and b

Tiarella cordifolia, photographed by Ashwin Srinivasan
fig. a Ashwin Srinivasan, CC BY 4.0

Tiarella cordifolia

Heartleaf Foamflower
Tiarella trifoliata, photographed by Peter Abrahamsen
fig. b Peter Abrahamsen, CC BY 4.0

Tiarella trifoliata

Threeleaf Foamflower

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Tiarella trifoliata Tiarella cordifolia 4 of 20 (20%)

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

What actually separates themon the record

Family Both Saxifragaceae. The family does not separate them.
Genus Both Tiarella. Congeners, which is why this is hard.
Flowering Peaks in April versus July. If the plant is in flower, timing helps. (n = 251 and 7,493.)

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