Spiranthes is a large genus of orchids that grow throughout the country. The generic name comes from their habit of having spirally arranged flowers on the spike. Spiranthes cernua has recently been split into four or more very similar species.
Their translucent, granular petals make backlighting an ideal way to photograph them, as in the posted image. I think they look like frost on a window. More direct light was used in the image shown here.