I was going to suggest the one with the narrower foliage was V. texana but decided to leave it. I still think there's two different species, unless it's the same plant.
I found those photos on the forestryimages site, but the leaves look much broader than on other photos which should be correct..
http://www.wildflower.org/gall...
The photo of V. texana on the next link looks like the narrow leaved one ..
http://src.sfasu.edu/~jvk/Pine...