notes Note the decumbent habit (the branches here were actually held horizontally and elevated a few centimeters above sand) with widely divergent and spreading branches, stem sparsely villous and (at least distally here) reddish. Some plants are open and straggly like this one; others are more compact, with shorter internodes and more tightly congested glomerules of involucres. This was photographed in a locale where this species has been collected before, see this CCH record.
Note the narrow but evident scarious margins along the involucre teeth (tapered at base and apex...see 3rd & 4th images in this series), taking this plant to C. cuspidata var. marginata in the key of Goodman's 1934 revision, via couplet choices A, B, CC, r, s, t, u, vv, x, yy. Goodman's species description can be read here. Two isotype images are here and here.
In Abrams 1944 ''Illustrated Flora of the Pacific States, Vol. 2'', the variety marginata is mentioned, but only the nominate form is illustrated (see here).
In the 1989 revision of Reveal & Hardham, this again keys to C. cuspidata via choices A, B, CC, DD, E, FF, G, HH but in their description they state C. c. var. marginata is not clearly distinct from the nominate form, and thus they do not formally recognize it.
To my eye, the cuspidate tepals in this population are very minute and don't really seem to provide a robust character for separating these plants from C. pungens
