THAT'S WHY THEY CALL ME "FLOWER"

Out and about in water vole country when I found this creature freeing itself from a spider's web. While I was switching on the camera, it landed on me to get its breath back for a while, which made taking the photo quite awkward. Anyway here it is, albeit damaged from the web. It fluttered off again after a few minutes and disappeared into undergrowth. I think it's just a small white, but possibly (??) a green-veined white. I'm sure there are experts out there who could tell me. The water voles were all too quick for me today - I heard several plop into the water, but saw none of them.