Prunelloides is a small growing mat forming salvia which is similar to arizonica and glechomifolia. They all have blue flowers and increase by runners. They are all also semi dormant in winter depending on how cold it is. Prunelloides will survive in all but the coldest parts of Australia.
Arizonica is the largest and best of this group but the others are of interest especially to collectors or people with small gardens.
Out of stock, go for glechomifolia instead.