Cladium jamaicense

About

Cladium mariscus is a species of flowering plant in the sedge family known by the common names swamp sawgrass, great fen-sedge, saw-sedge or sawtooth sedge. Previously it was known as elk sedge. It is native of temperate Europe and Asia where it grows in base-rich boggy areas and lakesides. It can be up to 2.5 metres tall, and has leaves with hard serrated edges. In the past, it was an important material to build thatched roofs; harvesting it was an arduous task due to its sharp edges that can cause deep lacerations.

Summary from Wikipedia