I mentioned Dicentra (bleeding heart) in my last post. Beautiful Wildlife Garden has a nice post about native bleeding hearts, which apparently are a good food source for hummingbirds. I was pleasantly surprised to see a ruby throated hummingbird checking out my nonnative bleeding heart last week, so I guess that's not a total fail even though it isn't native.
Going further back, there was also a recent post on Beautiful Wildlife Garden about black gum as a shade tree. There is actually a black gum cultivar ("Wildfire") with particularly attractive fall color. For people who don't want to plant yet another maple, this could be a nice alternative.
Finally, it's the time of year for flowering of robin's plantain, a small, spring flowering aster. I only recently learned of this plant, but my father has successfully propagated it from collected seeds and says that it does well in moist, partly sunny locations.