Our grasslands are under threat from invasive Category 1b pompom weed. This noxious plant overtakes grasslands and outcompetes indigenous grasses and shrubs. People are often tempted to cut the flowers for floral decorations, but this plant must not be transported. By law, pompom weed must be controlled if found growing on your property.
Peanut butter cassia
This shrub which is naturally found in tropical Africa has established across eastern and southern Africa. Despite the common name, the seeds and flowers are poisonous and toxic to livestock. It invades coastal bush, grassland and savanna, particularly in the warmer climates.
Drooping prickly pear
Numerous cacti have become highly invasive in South Africa. The drooping prickly pear or cochineal prickly pear (Opuntia monacantha) thrives in the more wet and humid lowlands of KwaZulu-Natal and the Eastern Cape. It is often seen along beachfront embankments.
A cochineal called Dactylopius ceylonicus is host specific and highly effective as a biocontrol agent. It greatly reduces the density of cacti. The Centre for Biological Control based at Rhodes University in Makhanda in the Eastern Cape is at the forefront of biological control for invasive cacti.
Mexican sunflower flowers between April through to July and is a prevalent invasive annual or perennial. It is found across coastal KwaZulu-Natal and the lowveld regions of Mpumalanga and Limpopo Provinces. The stems are rigid and strain and turn woody when the plants are mature. May eventually reach a height of 3-4 metres.
A climbing shrub or small tree which forms dense clusters and outcompetes indigenous vegetation. It thrives along drainage lines and infiltrates natural savanna and grassland. It is often overlooked for one of the indigenous acacias. Prolific in KwaZulu-Natal and Mpumalanga. Also called the mysore thorn.
The mallard duck (Anas platyrhynchos) is a common sight around city dams and parks. People are inclined to feed these ducks which encourages their population to expand. Mallards compete against indigenous waterfowl for resources and nesting sites. They also frequently hybridise with the indigenous yellow-billed and black ducks. This reduces the genetic integrity of these indigenous birds thereby hampering conservation efforts.
The common name Madeira vine is somewhat misleading as this climber comes from South America. It is also known as bridal wreath as it produces spectacular white fragrant masses of flowers between February and May. This creeper invades water courses, forests, plantations and urban areas at the expense of indigenous vegetation.
The lollipop climber is a climbing perennial growing 6 m in height and clambering up other plants. It has distinct five-lobed finger-like leaves. The fruits are rounded – initially green with white marks resembling tiny watermelon but turn bright red. This climber has been found around Durban and Pietermaritzburg and a few other spots along the KwaZulu-Natal coast.
There are two Category 1b Xanthium (cocklebur) listed under NEMBA regulations. The large cocklebur is widespread across southern and eastern South Africa where it invades roadsides, drainage lines, agricultural fields and river and stream courses. The heavy rains experienced over large swathes of South Africa in recent months has allowed this weedy annual herb to flourish.
This herbaceous shrub thrives in and around shaded kloofs, forests, and along streams and rivers where it can outcompete other shade-loving herbs and grasses. The plant is poisonous and the bright red berries resemble small cherry tomatoes. Originally planted as an ornamental, it is now a Category 1b invader and must be removed and destroyed.