Eichhornia. Water hyacinth are a free-floating perennial aquatic plant 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 in height. The leaves are 2 to 3 in across, and float above the water surface. The feathery, freely hanging roots are purple-black. An erect stalk supports a single spike of 8-15 conspicuously attractive flowers or deep lavender with white or pale purple throats. Water Hyacinthes bloom repeatedly from spring to frost in full sun.
These plants are hardy to zone 8. In areas where there are hard freezes, these plants will need to be put in a pail and set in a sheltered location. Hyacinth will grow on any water surface, indoors or out. Water depth needs to be at least 6 inches for them to freely float.