Thesium is a genus of shrubs and herbs parasitising partly upon the roots of plants growing around them; partly, because they also photosynthesise, but not enough for their growth needs.

The photo shows a Thesium plant in the Kogelberg flowering in November. Its five-pointed, white star flowers grow in stem tip clusters, the buds creamy yellow, surrounded by fleshy orange sepals. Leaves are tiny and sparse.

The plant may be Thesium strictum, the rootthug or in Afrikaans teringbos (tuberculosis bush). That plant is found on sandstone slopes from Namaqualand to Grahamstown (Privett and Lutzeyer, 2010; Bond and Goldblatt, 1984).