Senegal tea is a native of South America and was originally introduced into Australia as an aquarium plant.
Impacts:
Forms floating mats, blocking irrigation ditches, shallow dams and waterways, invades and degrades natural wetlands
Description:
An aquatic perennial that grows over the water surface, produces runners and floating stems up to 2.5 m long, grows as a rounded bush, shiny dark-green leaves are 5-20 cm long and grow in opposite pairs, stems are hollow between the nodes, allowing the plant to float, young stems are light green with dark-green blotches, young round stems become six-sided as the plant grows, flowers resemble white pompoms 15-20 mm in diameter, seeds are yellow-brown and ribbed
Control:
Before attempting control, report weed to the Bio security Queensland (part of the Department of Employment, Economic Development and Innovation), remove mechanically, place plant material in a sealed plastic bag, leave in sunlight to rot then burn or dispose of at a council-approved landfill tip, do not leave broken plant pieces in the area, apply herbicide
Source http://www.dpi.qld.gov.au