Lysimachia ciliata
Yellow loosetrifes have 5 yellow petals; this species differs from the others in a couple of ways. First, the edges of the flower petals are gently wavy or toothed. You can observe that in the photo above. Also, the flowers of this plant always face downward (nodding), such that you have to turn them over to see what they look like. And finally, the simple leaves of Fringed Loosestrife have hairy or “fringed” petioles. The leaf arrangement is opposite and the margins are entire (not toothed).
This is a plant of wet places that can grow 1 to 4 feet in height. I found it mixed in among assorted, sun-loving plants in a moist roadside area next to Big Stoney Creek in Giles County, and also along Tom’s Creek on the Deerfield Trail in Blacksburg.
See a similar species, Whorled Loosestrife, here.
VIRGINIA WILDFLOWERS 