An exercise in Biophilia
I'm pretty sure it's a Xysticus sp. crab spider
Yeah, I think it's X.cristatus. I have one at home in a pot which looks good for that species too. Haven't bothered with spiders for a while but since I've got a shiny new dissecting scope and I had a spider in a pot, well, it would be rude not to!.
or it could be audax of course ... tricky