Witches’ broom affects proteas, also Protea glabra. It is a plant disease causing a deformity in a woody plant, typically a tree, where the natural structure of the plant is changed. A dense mass of shoots grows from a single point, the resulting structure resembling a broom or a bird's nest.
Witches’ broom has many causes, including fungi, insects, mites, nematodes, phytoplasmas, viruses, mistletoes and dwarf mistletoes (although the broom is not a mistletoe itself). People can cause witches' broom through poor pruning practices.
The broom growth usually lasts for the remainder of the life of the host plant.
This occurrence of the phenomenon was seen in the veld at Kagga Kamma (Rourke, 1980; Manning, 2007; Coates Palgrave, 2002; iNaturalist; Wikipedia).