notes I was surprised to learn from studying the 2007 edition of the Marin Flora that there are only 4 species of Eriogonum recorded from Marin County (6 taxa including varieties), they are: E. fasciculatum (vars. foliolosum & polifolium), E. latifolium, E. luteolum (vars. caninum & luteolum), and E. nudum var. nudum.
The plant in the photo here is clearly E. luteolum, and it seems to me to fit the nominate variety...though the assignment of characters separating the varieties seem somewhat ambiguous and difficult to interpret. Moreover, there were hundreds of plants growing side-by-side in the population...with different individuals fitting one or the other variety as well as intermediates.
The couplet separating the two varieties in the Marin Flora reads:
c) Plants erect; involucres many and lateral; inflorescence unevenly branched...E. luteolum var. luteolum c') Plants prostrate to ascending; involucres few and lateral; inflorescence more or less evenly branched...E. luteolum var. caninum
The species comments in the Marin Flora list ''Carson country'' among the locales for var. luteolum, but only the Tiburon Peninsula for var. caninum.
To check the ID, I also consulted the Jepson eFlora Eriogonum key, as well as James Reveal's Eriogonum treatment and key on the University of Maryland web site (which is nearly identical to his FNA treatment & key). These treatments seem to imply (not wholly consistently) that var. caninum tends to have:
1) involucres mostly terminal, with significantly fewer lateral (vs. many lateral involucres, appressed to the stems, in var. luteolum); and 2) cauline leaves present, in addition to the basal leaves (vs. usually only basal leaves for var. luteolum).
The above distinctions are illustrated nicely in Doreen Smith's CalPhotos post of var. caninum here.
I guess this situation is not unexpected, as we *are* dealing with 'varieties' here (as opposed to subspecies), and Reveal noted in his description and discussion of E. luteolum that ''a sharp distinction between var. luteolum and var. caninum is not always possible''.