Anchored water hyacinth (Eichhornia azurea) is a Class 1 declared pest plant in some parts of Australia. Anchored water hyacinth is an aquatic plant, native to tropical America. It is closely related to one of the world’s worst aquatic weeds, water hyacinth (Eichhornia crassipes).
Impacts:
Smothers the surface of creeks, lakes and other water bodies
Description:
Looks similar to water hyacinth, glossy round leaves, attractive purple flowers
Source http://www.dpi.qld.gov.au