Blooms will tell for sure but the foliage reminds me a lot of Tricyrtis (Toad Lily), for comparison, click to enlarge the third photo here: http://www.onlineplantguide.co...
Most Tricyrtis I have seen have a thin stem, these plants look to have a thick stem. There is one which looks about right though, Tricyrtis formosana .. and the photos taken were in Georgia State Botanical Garden .