Distinguishable from wood ferns by compounded fronds. They aren't just lobed like wood fern, they are compounded again with an extra "thumb" on the first segment of each smaller portion of the fronds. As if a sword fern had more detailed sections. Overall impression vs wood fern is that it is "neater" in appearance, more geometric.
White (not yellow) ring around center of cup. The closest species I could find in Calflora was. Cyrptantha simulans. Scattered small colonies mixed into grasses and other wildflowers.