Elsewhere, other populations are in the Catawba River in South Carolina and in the Cahaba River in Alabama (where the plant is known as the Cahaba lily.)
Because of its rarity, the lily is being considered for the federal Endangered Species list. It once was more common, but large swaths of its habitat were submerged under huge lakes created by damming of rivers. Also, siltation from development, farming and logging has taken a toll in other rivers.
Early American naturalist William Bartram, who first saw the lily in the Savannah River near Augusta in 1783, praised its pleasing odor. Especially strong at night, the fragrance readily attracts pollinators to its big blooms, which last only a day. Its pecan-size seeds sink into rock crevices in the shoals and germinate there instead of floating into deeper water, where they would die.
A retired high school science teacher from West Point, Johnson fulfilled a longtime dream in 2008 when he signed conservation easements with the Nature Conservancy of Georgia and the Wilderness Network of Georgia to protect his 323-acre estate and its shoals spider-lilies from development. Even so, he fears that new development on the perimeter of his property may threaten the plant.
In the sky: The moon will be first-quarter Thursday, said David Dundee, Tellus Science Museum astronomer. Mercury is low in the west just after dark. Venus rises out of the east about two hours before dawn. Mars rises out of the east just before sunset. Jupiter is low in the southwest at dusk and sets in the west a few hours later. Jupiter will appear near the moon in Saturday night's sky. Saturn rises out of the east at sunset.