Bluebonnet seed pod

I went outside today for a picture and this is the more interesting thing I could find. A little bluebonnet plant was living in a crack between pavement and a stone post. The deer didn't find its flowers and I was waiting until the seeds matured to take them to plant in a bed. Today I noticed the pods were quite brown, so I reached down to take them off and discovered they were empty! Look at the pod. When it dries it apparently twists to throw out the seeds. All of the pods on the plant looked this way.