I would first check that this is not a synonym of any of the species listed for Brazil Myriam, here's the list for Brazil..
Acanthaceae Pseuderanthemum bolivianum Britton ex Rusby
Acanthaceae Pseuderanthemum congestum (S.Moore) Wassh.
Acanthaceae Pseuderanthemum detruncatum (Nees ex Mart.) Radlk.
Acanthaceae Pseuderanthemum exaequatum (Nees) Radlk.
Acanthaceae Pseuderanthemum heterophyllum (Nees) Radlk.
Acanthaceae Pseuderanthemum leptostachyum (Nees) Radlk.
Acanthaceae Pseuderanthemum macrophylum (Nees) Radlk.
Acanthaceae Pseuderanthemum modestum (Nees) Radlk.
Acanthaceae Pseuderanthemum riedelianum (Nees) Radlk.
Acanthaceae Pseuderanthemum verbenaceum (Nees & Mart.) Radlk.
A perhpas true photo of Pseuderanthemum reticulatum
http://en.wikipedia.org/wiki/P...