<Tr> <Td_colspan="2"> Eichhornia crassipes (Mart .) Solms </Td> </Tr> <P> Eichhornia crassipes, commonly known as (common) water hyacinth, is an aquatic plant native to the Amazon basin, and is often a highly problematic invasive species outside its native range . </P> <P> 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 in height . The leaves are 10--20 cm across, and float 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 8 - 15 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) or Amazon frogbit (Limnobium laevigatum). </P> <P> One of the fastest growing plants known, water hyacinth reproduces primarily by way of runners or stolons, which eventually form daughter plants . Each plant additionally can produce thousands of seeds each year, and these seeds can remain viable for more than 28 years . Some water hyacinths were found to grow between 2 and 5 metres a day in some sites in Southeast Asia . The common water hyacinth (Eichhornia crassipes) are vigorous growers known to double their population in two weeks . </P>

In which part of the world is water hyacinth a native plant