I believe this is Hesperolinon disjunctum, though it might conceivably go to H. californicum due to ambiguity at couplet 9 in the JM2 Hesperolinon key (i.e. 'Inflorescence generally dense' vs. 'Inflorescence generally open'). Although the pedicels in flower on this plant were shorter than on the others nearby (i.e. looking < 2mm)...the stipular glands were minute (vs. well-developed in californicum). Also, the petals on the plants here were smallish, compared to the typical size given for californicumin TJM2.

There are CCH records from near the locale here for both H. disjunctum and H. californicum. However, the latter record is the southernmost outlier on the CalFlora map here and somewhat removed from the other records for H. californicum. Furthermore, that record is annotated with two ID's: both H. californicum and H. micranthum!!? Finally, the Sharsmith record is very close to where these plants were found, and the locale is squarely within the recorded range for H. disjunctum.