May is, of course, the time for Mayapples (Podophyllum peltatum). These odd-looking plants are spring ephemerals that grow under the woodland canopy. They emerge and flower when the trees do not yet have leaves, then set fruit and vanish by midsummer.
Mayapples form clonal colonies–all of the stems in a group are genetically identical. These photos are of a colony on the Lake Forest College campus, just opening their deeply dissected, umbrella-like leaves (one or two leaves per stem), some producing a single flower bud. Mayapples contain podophyllin, a cytotoxic substance used to cure warts.