Long before autumn's Big Show, which, of course, is the turning of the leaves, there's a Little Show that starts in late summer. To find it, you have to take to the trails and the country roads and search the foliage that grows where it's fairly shady. Some of the ferns, the Hay-scented in particular, turn early, as does the Wild Sarsaparilla. But the poster child ushering in leaf-peeping season has got to be Poison Ivy, that famous look-but-don't-touch plant. Although PI is especially beguiling as it begins to lose its green color, its chlorophyll, in response to signals from the decline in daylength and subtle changes in the shade-filtered light, the warning still holds. While there's subtle beauty on display as the accessory pigment reds and oranges are unmasked, the foliage remains powerfully itch-inducing—and best admired and photographed from a distance.