Found in greenhouse
These are all over these woods, but this was by far the largest patch of them I came across
At Spectacle Pond Natural Area (also called Red Pine Natural Area) in Brighton State Park
On the Long Trail in the White Rocks National Recreation Area
White form of Cypripedium acaule
This is a scan of an old print from film. I don't have the exact date, but I believe the year was 1997, and the month was June.