I seemed to have overlooked this when voting; but now it catches my attention. It's a very appealing shot for reasons I can't quite discern. I love the "dust" in the upper-left corner and the duotone is lovely. Those thorns look positively deadly!
Different look at natural texture, the image meets the challenge adequately. From a technical standpoint, the image could use a little more contrast and better DOF control as the nature of the image demands a crisp sharp focus with perfect DOF control. The monotone feel hurts a little. A solid entry with some minor issues. As it is, a top forty contender.