Jeffersonia diphylla (L.) Pers.
Twinleaf is native to eastern North America and eastern Asia. The genus Jeffersonia is named for Thomas Jefferson by his friend, William Bartram, also a botanist. Twinleaf is rare now, considered threatened or endangered in Georgia, Iowa, New York, and New Jersey.
Identification: Twinleaf is so named because each leaf consists of two halves that are mirror images of each other, looking a bit like the wings of a green moth. These slow-growing perennials reach about 8" (20 cm) in size. Each leaf and flower occurs atop its own stem, and all the stems emerge from the base of the plant. Leaves are smooth-edged and two-lobed, and fairly unique in shape. Each flower is white, with 8 petals, 1-1½" (2.5-3.8 cm) in diameter. Fruits, about 1¼" (3.2 cm) high and 1" (2.5 cm) in diameter, are thimble-shaped, with a cap that makes them resemble a bell pepper.
Jeffersonia on Wikipedia
Jeffersonia diphylla at the Vanderbilt University Bioimages web site
Jeffersonia diphylla on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Jeffersonia diphylla at the Lady Bird Johnson Wildflower Center
Jeffersonia diphylla at the U.S. Forest Service Celebrating Wildflowers site
Jeffersonia diphylla at the University of Wisconsin's Robert W. Freckmann Herbarium
Jeffersonia diphylla on eFloras
Jeffersonia diphylla description by Thomas H. Kent, last updated 16 Aug 2013.