Australia.com provides a nice general overview of endemic (only in Australia) plant life, the most famous to many of us probably being the eucalypts tree- the sole food in a koala's diet!
Eucalypts tree. Image from Flickr. Creator: John Turnbull.
Below is a wattle tree, a kangaroo paw flower, and an emu bush, in that order (all from Flickr.com):