It is endemic to Monterey County, California, where it is known from the woodlands of the Central Coast Ranges.

This is an erect annual herb growing a hairless, waxy stem up to about half a meter in maximum height.

The fan-shaped lavender petals are often flecked with red and tinted with pink, each measuring one or two centimeters long.

This plant is very similar to, and historically confused with, Clarkia lewisii, which differs from C. jolonensis in that the former has a curved inflorescence with closely packed nodding flower buds, while the latter has an erect, widely spaced inflorescence.

[2] Some of the few known occurrences of this plant may actually be its sister species, making it rarer than officially listed.