There is a little park near me that has a section devoted to native Texas plants. I took this picture there. unfortunately it was in direct sunlight and the color is washed out. The flower is entirely the lavender/purple you see parts of. I'm adding a better picture. Anybody know what it is?
That's certainly looks similar, but a couple of things don't agree with the description given for the Obedient Plant These plants don't reach a height of more than 18" and the leaves do not have sawtooth edges. The flowers in the pictures I posted are about 3" tall. The pictures of Physostegia virginiana look much larger. This picture was snapped accidentally but it gives an overview of the plant though mixed with other foliage. As you can probably tell I'm pointing the camera down indicating the plant are small. I made the image size large so you can look closely at it.
Other members of the genus Physostegia have a similar look, such as Physostegia angustifolia, Physostegia longisepala and others. But they are all too high and their flowers too tall.