Discaria

Discaria is a genus of 6 species of flowering plants in the family Rhamnaceae, native to temperate regions of the Southern Hemisphere, in Australia, New Zealand and South America. They are deciduous thorny shrubs or small trees growing to 2–5 m tall. They are also non-legume nitrogen fixers. Many of the world's Discaria species qualify as xerophytes in the true sense of the term, and the Australian species are no exception. They frequently occur on porous or well-drained sites and on soils of low fertility. Some species can fix nitrogen from the atmosphere with the help of symbiotic bacteria (Frankia) that form nodules in their roots....read more on Wikipedia.