There are four species of Leersia in Florida. They are perrenial aquatic grasses. Southern cutgrass, Leersia hexandra, is the most common and occurs throughout Florida. Leersia species grow in very wet communities: ponds, lakes, creeks, floodplains, canals, marches, swamps. Southern cutgrass has wiry, leaning stems that grow 2-4’ long from above- or below-ground runners. Stem nodes are hairy and root at the lower nodes. Leaves are flat, 1/8 – ¾ inch wide, and 3 – 12” long, tapering to a point. They are sandpapery on both sides, with sharp leaf margins that will cut. Ligules are papery and visible with the naked eye. The inflorescence is compound, 1-6” long, with a few thin branches. Flowers are flattened, ridged, ¼” long, with stiff short hairs. The fruit is flat, ¼” long and somewhat reddish in color.
Southern cutgrass – Leersia species
This genus of aquatic grasses includes about four species in Florida. Southern cutgrass often forms floating mats in shallow waters, floodplains, and swamps throughout Florida. The wiry, leaning stems of cutgrass typically grow to 2 to 4 feet long. They grow from above or below ground runners. The stem nodes are hairy on the upper stem and rooting at the lower nodes. The leaves are flat, firm, and thin. They are one-eighth to three-quarters of an inch wide and 3 to 12 inches long, tapering to a point. The leaves are sandpapery on both sides. The leaf margins of cutgrass are sharp and will cut. Cutgrass ligules are papery and can be seen with the naked eye. The compound inflorescence is from 1 to 6 inches long, and has only a few thin branches. The flowers are flattened and ridged, and up to one-quarter inch long. They have stiff, short hairs. The fruit also is flat, up to a quarter-inch long, and is reddish in color. The aquatic cutgrasses have hairy nodes on the stems. The leaves are sandpapery on both sides and have sharp, cutting leaf margins. The inflorescence is small, with a few thin branches. Its flowers are flattened and ridged, about one-quarter inch long.