I have two Barleria and they are fabulous drought tolerant plants that flower all through the year. I grow Barleria 'Purple Dazzler' in hanging baskets and in the ground. It will only reach around half a metre and grows well in both sun or part shade.
I also grow Barleria 'Purple Gem' - a shrub which will reach around one metre and has beautiful green, white and purple leaves. It bears the same lovely mauve flowers and is ideal for either a sunny or part shaded position. My 'Purple Gem' is in the ground and is a very colourful addition to the garden bed.