This keyed well to Gilia achilleifolia ssp. multicaulis in the Gilia key of TJM2. Note the white corolla tube, which is a key character. Another item of interest is that the calyces here are gland-dotted, whereas all other current CalPhotos posts of Gilia achilleifolia ssp. multicaulis have non-glandular calyces. But this is consistent with the Jepson eFlora description, which states the calyx can be ''tufted-woolly-hairy or glandular''.

This taxon is listed under G. multicaulis on pg. 352 of The Flora of the Mount Hamilton Range by H. Sharsmith, and a voucher by Sharsmith from very nearby the location here is recorded at this CCH link. Apparently the form here with solitary flowers on fairly long peduncles was formerly referred to as G. peduncularis Eastwood (original description here), which Sharsmith treated as synonymous with G. multicaulis stating:

''...the Mount Hamilton Range material shows every intergradation between the cymosely clustered, loose glomerules of flowers in the inflorescence of typical G. multicaulis, and the pedicelled, solitary flowers in the open, cymose inflorescence of typical G. peduncularis.''

G. multicaulis, in turn, was later subsumed as a subspecies of G. achilleifolia by Verne and Alva Grant (see here). The

There are two environmentally controlled 'sun' and 'shade' variants of G. achilleifolia, according to the paper:

Grant, V. 1954. Genetic and taxonomic studies in Gilia. IV. Gilia achilleaefolia. El Aliso 3: 1–18.

Field observations cited there indicated plants growing in sunny situations were taller, with glomerate inflorescences of many (larger) flowers on short pedicels (1-2mm); while plants growing in shady situations were shorter, with solitary (smaller) flowers on long (15-20mm) slender pedicels. Also, the sun plants were generally cross-pollinated by insects, while the shade growers were typically selfers. Seeds collected and grown in experimental gardens from both of these variants behaved like the sun variant when grown in full sun, and the the shade variants when grown in shade...so the associated morphological characters were presumed to be environmentally induced. In summarizing the variation in G. achilleifolia overall, Grant stated that:

''There is complete intergradation between the robust large-flowered capitate forms of sunny places (exemplified by the Douglas collection of Gilia achilleaefolia), through spreading small-flowered types growing in sunlight (exemplified by the Douglas specimen of Gilia multicaulis), to weak plants with a few small flowers on elongated pedicels in shady woods (the equivalents of Gilia peduncularis Eastw.). These various types have no well-marked geographical segregation.''

If my understanding is correct, in the Grant's circumscription, the two subspecies G. a. achilleifoloia and G. a. multicaulis corresponded, respectively, to the 'sun' and 'shade' variants mentioned above.

The plant in my image here was actually photographed in full sun at midday...but it was growing on a steep north-facing slope and thus, in terms of in overall exposure, likely experienced shade for much of the day in the spring growing season.