Water chestnut is an annual, rooted aquatic plant with a leafy rosette that floats on the surface. Stems can reach up to 16 feet, supporting two types of leaves. Submersed leaves are feathery, whorled along the stem and up to 6 inches long. Leaves are triangular, 1 to 2 inches long, waxy and have toothed edges. Leaf stems have a bladder-like swelling that provides buoyancy. Flowers are small, white, have 4 petals and bloom from mid-July to fall frost. The fruit is a one-inch wide woody nut armed with 4 stout barbs. The sharp barbs are a painful hazard to swimmers and bare feet.