Three-square is frequently found growing in fresh water to brackish marshes along the peninsula, central and western panhandle of Florida (Wunderlin, 2003). It blooms from spring to fall. Scirpus pungens occurs almost always under natural conditions in wetlands. The entire plant is eaten by geese and muskrats.
Three-square is a bulrush sedge. stems sharply triangular, to 3 ft. tall; leaf blades very few, to 8 in. long, strongly folded; inflorescence a cluster of 1-5 brown spikelets, at stem tip (but looks like on the side of the stem); bract as in other species: appears as a continuation of the stem above the inflorescence, to 5 in. long; spikelets cone-shaped, brown, to 3/4 in. long, scales spiral and overlapping, scales attach in a small V notch; nutlet with 4 sharp bristles.