Aesculus parviflora, bottlebrush buckeye 
I love this shrub! It has a loose form, getting to be about 8' tall and wide. It produces spikes of white, nectar-licious flowers in the summer and large seeds in the fall. It does well in rich, moist soil such as is commonly found at the bottom of a shady slope.
Eurybia divaricata, white wood aster 
This is a wonderful plant for dry, shady areas. It has vaguely heart-shaped leaves and will spread slowly to form a clump of plants 1-2' tall. It typicallyflowers in the late summer, once many of the other summer blooms have past, but before the fall bloomers get going.
Tipularia discolor, cranefly orchid
This is my favorite woodland plant in winter, when you can easily spy its leaves peeking through the leaf litter. In the warmer months, the leaves disappear and the orchid sends up a shoot about a foot tall with pale flowers.
Chrysogonum virginianum, green-and-gold 
This is a very low-growing, spreading, evergreen perennial. It makes a great groundcover in dry shade, and can tolerate about a half-day's sun. It produces quarter-sized yellow flowers in the spring. It would be a great replacement in the landscape for invasive plants such as English ivy, vinca (periwinkle), or liriope.
Hexastylis arifolia, arrowleaf ginger or little brown jugs 
This cute little, slow-growing, evergreen plant thrives in well-drained shade. This is a wonderful plant for dry, shady areas. Its brownish-dark purple flowers are produced underneath the mottled, heart-shaped leaves, so you have to make an effort to find them.