This flower is, as the title suggests, a mystery. This one was photographed at Gouldsboro State Park, and I have encountered it only once before, down at nearby Tobyhanna State Park.
The blossom is delicate, smaller than a quarter in size. It grows from floating mats of vegetation in shallow water, although it appears to be separate from the floating mass. I picked one up; its stem and roots trailed several inches downwards.
The shallows at Gouldsboro were filled with it, tiny pink spots amid the lily pads and hummocks. The blossom itself is somewhat reminiscent of an orchid, but my Google searches have turned up empty. It doesn’t appear to be an invasive species, as those are well documented. But I just don’t know – sometimes not knowing the right question to ask makes the answer hard to come by.