Water hyacinth is a free-floating perennial aquatic plant (or hydrophyte) native to tropical and sub-tropical South America. With broad thick glossy ovate leaves water hyacinth may rise above the surface of the water as much as 1 meter (3 feet) in height. The leaves are 10ââ¬â20 cm (4ââ¬â8 inches) across on a stem which is floating by means of buoyant bulb-like nodules at its base above the water surface. They have long spongy and bulbous stalks. The feathery freely hanging roots are purple-black. An erect stalk supports a single spike of 8ââ¬â15 conspicuously attractive flowers mostly lavender to pink in colour with six petals. When not in bloom water hyacinth may be mistaken for frog's-bit (Limnobium spongia[3]) or Amazon frogbit (Limnobium laevigatum).