Pink powderpuff flowers that attract hummingbirds, finely dissected compound leaves, and the classic form of a small savannah tree: pretty much everybody knows this plant as Mimosa, though of course it isn't a Mimosa. Here in the Washington DC area, we're about at its northern limits though in theory it's a USDA Zone 6 plant. As you go north you see very few specimens; as you go south, this time of year, you see gazillions of them. Whole interstate exchanges are populated by Mimosas. They seed prolifically and might take over the south if it weren't for a vascular fungus that eventually dooms any individual tree.
This cultivar has reddish/brownish leaves hence the name. I have always liked Mimosas for, well I like everything about them, but have never felt as though they were plants that needed purchasing. Like Redbuds, seedlings are abundant around a mature specimen. They're easily distinguished by their feathery leaves, easily transplanted, and grow as fast as any tree, 2,3,4 feet a year. The only problem is that this cultivar, 'Summer Chocolate' is really really nice, but you have to buy it to get it.