WEBPurdue Agronomy — Turfgrass Science. Yellow nutsedge (Cyperus esculentus) is a troublesome, dificult-to-control weed that is often found in turf areas (Figure 1). It is also called chufa, nutgrass, or watergrass. It is important to remember that yellow nutsedge is not. a grass or broadleaf weed, but a sedge.