This plant is called Ruellia brittoniana in the book "1001 Garden Plants in Singapore, 2nd Edition, page 392". In the book "Tropical Flowering Plants by Kirsten Albrecht Llamas, page 37", it is called R. tweediana while R. brittoniana is a synonym. A search done in the Germplasm Resources Information Network (GRIN) website indicated that R. tweediana is a synonym of R. simplex. Further explanation on why R. simplex should be used is found in an article by Ezcurra C & Daniel TF. Simply, R. simplex is the oldest name and therefore, should be adopted.