The feathery, freely hanging roots are purple-black. Water hyacinth is a free-floating perennial aquatic plant (or hydrophyte) native to tropical and subtropical South America. An erect stalk supports a single spike of 8–15 conspicuously attractive flowers, mostly lavender to pink in colour with six petals. They have long, spongy, bulbous stalks. The leaves are 10–20 cm (4–8 inches) across on a stem, which is floating by means of buoyant bulb-like nodules at its base above the water surface. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 m (3 ft) in height.