May apple (Podophyllum peltatum) is an exotic-looking member of the barberry family.
The plant consists of a long, thick stalk from which flares an umbrella of irregularly-lobed leaf, with anywhere from 5 to 9 lobes. I read that these get "up" to 1' across, but I routinly get some over 15". I planted a half dozen and the second year they formed a nice little canopy. Within a few years they had tripled.
They migrate around during the dormant season and like to find rocks or walls for support. A few weeks after sprouting and spreading their umbrellas, they develop odd-looking round seed fruits that hang from underneath, along the stem. The fruit is edible, hence the name, but not the seeds or any other part of the plant.
Like many shade perennials, may apples need to be watched so they don't wilt in the heat. But unless burnt, they will revive with some evening sprkinkling and can last into July. Well worth it. A breathtaking area native plant that makes me wish I'd planted it en masse.
For more about native plants, especially those that do well in shade/moist areas, see the "book" on this website, Gardening with Native Plants in Shady Evanston.