[jabberwock]

Cleaver, sticky willy goosegrass (and a few other variations) are all the same thing.

I know that guinealynx says that young wood sorrel leaves are OK in small amounts, but I would be slightly wary because there are a LOT of different plants called wood sorrel (according to wikipedia there are over 800 oxalis species and "many of them" are called wood sorrel), so unless you know that your wood sorrel is exactly the same as the one guinealynx is talking about (and the wood sorrel near me is definitely different!) I would avoid it.

Ordinary sorrel also has quite high levels of oxalic acid so I avoid that too, I've got easy access to lots of better leaves to give.