When you see plants growing in the wild, where they can choose where to grow it gives you a veray good idea of where to plant them successfully at home.  Also why, in some instances you can be unsuccessful if trying to grow them in damp or clay soils.

I often recommend Euphorbia, Sage or other Salvias and Cistus (rock roses) as a great foliage/ colour combination for very dry areas.  And when you see where they naturally thrive it is truly amazing just HOW DRY they like it as seen here where all the lime green in the distance is naturalised Euphorbia on Pag Island.