pacific waterleaf--toxic look-alike?

I came home from the woods today with a bag of pacific waterleaf planning to mix it in with some salad greens or maybe steam some, and as soon as I tell my housemate what it is she tells me there's a plant that looks very like waterleaf that's poisonous.  This is the first I've heard of it, and she heard this a year ago and can't remember the name of the other plant or any other details.  Does anyone have any ideas what plant she might be talking about?  I want to make sure I can distinguish them, though I've never had any problems.

I'm new to waterleaf myself, but maybe baneberry or ranunculas (buttercup family) or geraniums??

Could look similar to a novice.