Difficult to see from your photo, but compare your plant to Angelonia for a possible match.

Thank you, looks like a distinct possibility. The leaves look similar, as does the size, but I haven't seen the flowers cluster quite like that. But then again, Angelonia requires full sun and these guys are NOT getting it. I'll post another pic in a minute of it isolated from weeds.

Isolated plant.

Blooms.

Angelonia.

Eeek! Thank you! These babies are getting relocated! :)