Are there cacti in Australia

The great majority of the land mass of Australia is either arid or sem-arid, there is very little surface water, the rain fall is low and there are very few rivers that actually run other than immediately after heavy rain.

Some of the larger deserts are the Great Victoria Desert, the Gibson Desert, the Tanami Desert, the Great Sandy Desert, the Little Sandy Desert, Sturt Stony Desert, the Simpson Desert. That accounts for most of the west of the continent, nearly two-thirds.