These flowers are in the orchid family and are saprophytic. They do not have chlorophyll that most plants use for food production and therefore do not have green leaves. They derive their nutrients from decaying organic matter and because of their dependence on that they may be abundant in one part of a forest one year and completely absent there the next. Because they live in such close symbiotic association with soil fungi they cannot be be cultivated.
While I was slithering on my back through the tall grass like an inverted snake, stalking these wild orchids, I heard some noise in the thick brush off the trail which I first attributed to my dog, except that when I glanced up, she was quite close to me. It happened again a quarter of a mile further up the trail when I was in the prone position stalking a stand of Pipsissewa. I suspect it was a cougar just trying to figure out exactly who was slithering around in the middle of his living room. I would certainly do the same.