Great capture - a concise way to sum up the challenge. I love the textures and the detail of the water beads on the thistle. The backlighting keeps this from being an amazing photo - but it's still a very good one, your sense of space and DOF is very nice.
I like the idea and great work finding the subject. I find that the photo of the subject is too dark against the lighter background. Maybe try a different angle
A bit dark, and the left thistle is out of focus. I like the depth of field - does a great job of highlighting the subject. I also like the water on the right thistles - very nice touch.
Somewhat dark and lacks 'punch' (not colorful enough). Maybe use a flash or wait until the sun shines on the plant? Interesting plant, though. I like the blurry background - nice depth of field! Maybe a close-up will make it even more interesting and eye-catching. Great attempt!