Back in 2004, when the only real wildflower identification guide I had was Audubon’s North American Wildflowers Eastern, I identified this flower as Fire Pink – Silene virginica. I was wrong.
The blossoms of Fire Pink (aka Scarlet Catchfly) and Roundleaf Catchfly are similar, but in a recent review of photographs I noticed differences between them. S. virginica has narrower petals, and doesn’t have the pronounced ‘second spike’ along the outer edge of the petal. The coloring of S. rotundifolia isn’t quite as deep as Fire Pink, either. There are three deep red Silene species, S. virginica, S. rotundifolia, and S. regia (Royal Catchfly.) S. regia doesn’t have the deeply cleft petals, so that’s not an option. S. virginica is noted for its cream-colored anthers; not so with S. rotundifolia. While USDA Plants Database doesn’t have Roundleaf Catchfly listed in Polk County, Tennessee, where I photographed this specimen, and I don’t have photographs of the rest of the plant (it was back when I naively thought you could identify a wildflower species from the blossom,) the notable difference in the blossom shape from S. virginica seems to provide ample evidence that this is Silene rotundifolia.