Flora of North America species comparison

Clarkia dudleyana is a rather widespread species in California, known primarily from the central and southern Sierra Nevada foothills, the Tehachapi Mountain area, the Transverse Ranges, and the Peninsular Ranges, ranging from Tuolumne to Riverside counties, sporadically in the north to Nevada County and in the south to San Diego County

Clarkia dudleyana is morphologically most similar to C. biloba and C. modesta, but molecular data suggest that the relationship is not close. On the basis of chloroplast DNA sequence, C. dudleyana and C. heterandra are closely related.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Clarkia lassenensis is found primarily in the northeastern counties of California, south-central counties of Oregon, and northwestern counties of Nevada, with a few outlier collections from Alpine and Placer counties in the Sierra Nevada, and from northern Mendocino and Glenn counties in the North Coast Ranges.

Clarkia lassenensis is morphologically most similar to C. arcuata and C. gracilis. At one time, C. lassenensis was considered a probable parent of the tetraploid C. gracilis but cytogenetic and molecular sequence data indicate that an unknown related species, presumably now extinct, was involved. Clarkia lassenensis can be distinguished readily from C. arcuata by flower size, position of the stigma, and pubescence of the immature capsule, and from C. gracilis by having immature capsules with eight grooves rather than four.

(Discussion copyrighted by Flora of North America; reprinted with permission.)