Cotula australis is a species of plant in the daisy family known by the common names Bachelor's Buttons, annual buttonweed, southern waterbuttons and Australian waterbuttons. This small plant is native to Australia and New Zealand, but it is known in other areas of the world as a common weed (South America, California, Mexico, South Africa, etc.).Cotula australis grows low to the ground in a thin mat with some slightly erect, spindly stems.