I like the detail. However, my eye isn't sure if it wants to look at the thistle (?) itself, or its shadow -- it keeps jumping back and forth. It might work a bit better if the shadow were closer to the plant.
I don't mind the dual-subject nature of the shot but I see how it could be remarkable in that regard. Nice use of lines, excellent choice to avoid either stem coming out of the corner. I might try a tighter crop on the vertical. The overhead space I don't believe benefits the image. The crop may not work, but you owe it to the image to try, I think.
I think the duotone (is it duotoned or tri- or quad? I can't tell) is a good choice over the standard black and white where this image is concerned.