This is a hirsute (course haired), erect or prostrate shrub of moist areas to 3m high. It sometimes has inflated pneumatophores (vertical roots emerging from the water) arising from submerged or buried roots. If a branched is bent and touches the ground it will root at the nodes (growing point from which leaves arise).
Leaves are alternate, oval to lance-shaped or elliptic with a narrowed base.
Flowers are yellow and born singly in upper leaf axils, with 4-5 petals to 25mm long. Flowers Spring to Autumn.
Fruit is cylindrical, 4-angled, to 20mm long. Fruit is readily dehiscent (opens easily at maturity) to disperse its seeds. Seeds are in several rows and free (not attached).
Sources & References
"Plantnet FloraOnline" (2005) http://plantnet.rbgsyd.nsw.gov.au/
For photos of plant in flower and more information visit
For acquatic weed control information visit
Prepared by Justin KY Chu, July 2005
Checked by IEWF, January 2007