Wildflower garden

This is a part of my wildflower garden- though in this area flowers won’t be appearing - just foliage. I took the photo because everything looked good with the sun shining from behind. One puzzling thing is a shadow - it’s low down on the right, on a well lit-up flat leaf. It looks like part of a cog wheel - the sort they have in old watches. But I can’t work out what it is! I didn’t see it till I looked at the photo on my computer screen!

Very sunny today but there was a cold north wind.