Southern hemisphere arid zone vegetation
The southern hemisphere continents of South America, South Africa and Australia support a unique vegetation adapted to low rainfall and poor soils. Leaves are often thick, and filled with volatile oils (you will notice the strong aroma of essential oils in the house) both of which deter insect predation. As well as evolving in parallel, there are some striking links between these now well separated continents, notably in the plant families Proteaceae and Restionaceae. These links reflect a period of history 100 million years ago, when the continents were linked into a super-continent - Gondwanaland