The inclusion of Navarretia breweri in this flora is currently based on a single historical collection, Christ 4475 in 1934.  Curiously, of the two known duplicates of this collection, the one in New York Botanical Garden (NY1012653) gives the location as “Boise”, but the one at The College of Idaho (CIC11625) places it instead in “Caldwell”.  Flowers on both have faded, making it difficult to confirm the diagnostic yellow color.

If the species does (or did) in fact occur within the flora’s boundaries, it is most likely in South Boise, but could alternatively occur in the Conifer Zone or Lucky Peak biogeographic units.