What does it look like?
Senegal tea is a hardy, semi-aquatic, perennial herb. It grows in damp soils, usually rooted on the edge of waterways but can also survive and continue growing when completely inundated. Suitable habitats include wetlands, streams and degraded waterways. It can form rounded bushes up to 1.5m tall or scrambling mats of tangled stems that spread out over water bodies.
Leaves are dark green and opposite, shiny and hairless. Larger stems are hollow, making them buoyant in water. White, clover-like flowers are present during summer. Similar in appearance to alligator weed or willow weed, except that the margins of its leaves are bluntly serrated.
Why is it a problem?
Senegal tea grows very quickly. It can rapidly cover water bodies with a floating mat of stems that displaces and out-competes native plants. The effects of flooding are made much worse because infestations block drainage channels. Recreational activities and irrigation may also be affected.
Senegal tea can reproduce by seed and vegetatively from stem fragments. Recent research has shown that seed production in Queensland is extremely low, which indicates that reproduction by seed is not very important there. Vegetative spread occurs when a stem or leaf breaks off and grows roots.