Does not appear to be nutsedge. Growth habit and emerging flowerhead are not consistent with that genus (Cyperus, not Carex)

Yes, I was doubting nutsedge, because the flowers her are smaller than nutsedge flowers, and I don't see any root nodules that are characteristic of nutsedge. Good point that nutsedge isn't even Carex, though it is a sedge, and both Carex and Cyperus are Cyperaceae. I gather that identifying different varieties of Carex isn't easy.

I gather that identifying different varieties of Carex isn't easy.

I'll say!! It's a singularly large genus with a global presence and a wide range of appearances and habitats.

Even with extensive formal ID training, I find identifing grasses and grass-like plants beyond the genus level challenging at best.