We northerners get to live vicariously through posts like this! That Abe Darby is stunning!!! I had an AD; it overwintered, but just barely and then over the next 2 years it petered out. Yours is lovely!! Carol

Oxalis fabaefolia? Comes up twice in a year. Leaves first - no flowers. Then leaves and flowers in autumn.

Peonies need sun and water when it gets dry, other then that mine went 15 years without anything other then mowed in the fall and water when it did not rain for long periods. We moved and they came with us last year in the summer.

There are so many varieties of wild grapes (hundreds) I find it almost impossible to identify most of them. Generally you can fit them into a broad category at best. Then there's the possibility that it's not wild and was planted by a previous owner. Since you said they are growing near a stream I'm going to guess they have a thick dark purple skin (when ripe) and VERY tart flavor. I've found such a variety growing near streams in my area as well. I tried desperately to identify it but with little luck. I narrowed it down to some sort of stream bank grape. If you want to take a shot at it, base the identification mainly off of the leaves, as all varieties are slightly different.