- conspicuous perennial with stems usually 1-2 feet tall, sometimes taller but often falling over and rooting at nodes
- leaves opposite, linear, smooth, usually 3-4 inches long and less than 1/2 inch wide
- flowers with 2-lipped corolla, pale lavendar with both darker and lighter patterns in throat
- grows in mountains of Tamaulipas and San Luis Potosi and near sea level on the Rio Grande delta (Cameron, Hidalgo and Willacy counties)
- found in various moist, partially shaded habitats
