Water hyacinth - Eichhornia crassipes

Water hyacinth is a free-floating perennial aquatic plant (or hydrophyte) native to tropical and subtropical South America.[5] 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.[6] 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. They have long, spongy, bulbous stalks. The feathery, freely hanging roots are purple-black. An erect stalk supports a single spike of 8–15 conspicuously attractive flowers, mostly lavender to pink in colour with six petals. When not in bloom, water hyacinth may be mistaken for frogbit (Limnobium spongia[7]) or Amazon frogbit (Limnobium laevigatum).