False Indigo (Baptisia australis) is a big perennial thats tough as nails, false indigo kicks off summer with spires of pure blue (cultivars come in a variety of other colors). Its rounded form makes a great contrast to the verticality of prairie grasses.
Myoporum parvifolium Creeping boobialla white is a dense ground cover that anchors itself and continues to spread. Fleshy green foliage and dainty white flowers in summer. Prefers a full sun to part shade position.
Wahlenbergia communis (Native Bluebell) is a tufted or open perennial herb growing to a height of and spreading It has blue bell shaped flowers on long stems in summer. It is found in all mainland states of Australia