Yes The name is right, Ruellia brittoniana, the one in the photo is the species it self which can get to 1m and often a real pest in the garden,as it will seeds its self in every crack, between pavment ets.
In the last 8 years or so there is a dwarf vraiety 'Texas superstar' which is beautifull, it doesnt seeds it self freely,
about 40cm,bigger flowers in Pink, White and Purple.
It blooms in 2-3 waves that last long time.