Some sources list these as limited to the Grand Prairie and central Arkansas Counties. I can tell you that they abound in the wild in Randolph County in NE Arkansas.
Was just thinking about you the other day that I haven't seen anything new from you, and there you were this morning at the top of my favs! These are really something aren't they?! Sort of looks like a morning glory in the middle part, but those spikey things shooting off around it really make it! Also nice job on the metering, I have a hard time with white objects, yours looks fantastic.