I've seen these plants blooming along the roadsides up here for over a month now - quite pretty actually. They reminded me of Salvia, and Google images seem to support this, with Salvia hispanica looking quite similar. Perhaps I can grow my own Chia pet. Waddya think this is?
I'd be going with Salvia as well. S. hispanica is a fairly good match, and is present in the Panamanian highlands.