With big leaves and bright purple flowers, the water hyacinth is a beautiful sight. Air-filled stems on each leaf keep the leaves and flowers above the water like a small floating garden. Its attractive appearance has led to the plant, which is native to the Amazon basin, being introduced around most of the major continents. This has created huge problems in each of these places. The water hyacinth has been called the fastest-growing plant in the world. Over just one season, a plant the size of your hand can grow into a sprawling patch of more than 600 square meters. These mats block light from reaching the water below, ruining habitats for water-dwelling animals. The water hyacinth also eats up oxygen in the water that other plants and animals need and leaves lots of dead plant parts in the water over time. Getting rid of this eye-catching plant is difficult because it produces many, many seeds, which can survive for years before maturing into a full-grown plant. People may think they've killed all the plants in one pond, only to see the weed pop back up a year later from these hidden seeds.