Both Arctostaphylos

Arctostaphylos glauca vs Arctostaphylos patula

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

Confused 6x by our model Same genus Arctostaphylos Method published

Side by sidefigs. a and b

Arctostaphylos glauca, photographed by joergmlpts
fig. a joergmlpts, CC BY 4.0

Arctostaphylos glauca

Big Berry Manzanita
Arctostaphylos patula, photographed by Annika Lindqvist
fig. b Annika Lindqvist, CC BY 4.0

Arctostaphylos patula

greenleaf manzanita

How often our model gets it wrong measured, not estimated

When the plant was The model said How often
Arctostaphylos glauca Arctostaphylos patula 4 of 18 (22%)
Arctostaphylos patula Arctostaphylos glauca 2 of 17 (12%)

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 Ericaceae. The family does not separate them.
Genus Both Arctostaphylos. Congeners, which is why this is hard.
Flowering Peaks in January versus May. If the plant is in flower, timing helps. (n = 1,582 and 1,606.)

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