here is Cyperus strigosus, which i see all over the place in moderately damp situatio s. you can see it in the foreground, very full and spikey. Behind it is a taller looser yellower sedge.
here is a closer comparison, C. strigosus on the right
even closer, notice strigosus on the right has long thin green keeled flower scales while the plant on the left has more smaller stubby browner scales
so, today i went back and dug up one of the flimsier sedges and found tubers. that's a tuber growing off of one of the roots beneath the sedge. It's Cyperus esculentus, nut sedge. the tubers are supposed to be edible. if i find a bigger mature patch maybe i will try. probly gotta boil or roast them?
I will try posting my pics and drawings of 18 sedge species later.