Nutsedge

Nutsedge is a grass-like perennial weed with triangular stems that invades lawns and spreads through underground tubers.
Cyperus spp.
Origin: Worldwide
USDA Hardiness Zones: 4-10
Pros;
Tolerates wet areas – thrives in soggy soil
Cons:
Grass lookalike weed – stands out in lawns
Spreads underground – tubers are hard to eliminate
David Kim