Note the relatively thin and delicate stems and the small flowers (about 7-8mm), occurring singly or in pairs (rarely 3's) at upper nodes, with pedicels (mostly) longer than calyces throughout the entire inflorescence (i.e. not shorter above). Other characters for this species are: leaves well-spaced, narrowly oblong-linear and (mostly) entire; inflorescence non-glandular; and calyx lobe tips acutely long-tapered and extending beyond fruit. The Jepson eFlora Collinsia key separates the two currently recognized subspecies via the couplet:

    15. Corolla 5–8 mm, throat barely angled to tube, pouch hidden by calyx ..... var. collina

    15' Corolla 7–20 mm, throat strongly angled to tube, pouch generally evident to prominent ..... var. sparsiflora

The size of the corollas here points towards ssp. collina (though technically they're within the overlap of the intervals given for both varieties).

I'm not familiar with the subtleties of interpreting the character ''pouch hidden vs. generally evident or prominent''...though I'd guess Jake Ruygt's image illustrates the ''prominent'' case for ssp. arvensis, which is currently subsumed under ssp. sparsiflora. But I wouldn't think the pouch (= upper base of corolla tube?) is especially hidden in my images...or many currently posted under var. collina (e.g. Steve Matson's image here).

And, again, the subtleties of interpreting the character ''throat strongly angled to tube'' seem tricky to me. I understand the term ''throat'' to typically mean: a gradually flaring portion of the corolla between a basal, more-or-less parallel-sided, cylindrical 'tube'; and the more spreading and separated lobes of the ''limb''. Is the ''tube'' here very short; localized near the point of attachment to the receptacle; and contained within the tube of the calyx? And is the longer, angled, cylindrical portion of the corolla...between near its base and the lips (which appears ''tubular'' in the vernacular sense) considered the throat here? That would seem to be consistent with Munz's Collinsia description, which states' 'tube short; throat well-developed'. But if that's the case, then both varieties (and indeed most Collinsia species) would seem to have 'throat strongly angled to tube'.

On the other hand, if the plane roughly defined by the upper and lower lips is taken as transverse to the 'direction of the throat' ...then I'd say the throat is rather distinctively ''strongly angled to the tube'' in the individuals I photographed here.

Since I'm not clear on how to resolve the above mentioned characters, I'm leaving this at the species level for now.