The plant thrives in wetlands and riverine areas, but also invades roadsides, old lands, and drier veld. Verbena is often found side-by-side with pompom.
A tall erect herb with distintive quadrangular (sharp-edged) stems of 1-2.5 metres in height.
Upper branches are 4-9cm long. Flowers occur in clusters and are mauve in colour.
In harhser conditions the plant grows smaller and finer.
Manual control is possible. Pull the plant out with its roots, preferably after good soaking rain.