This is the first time I've seen flowering Cypripedium guttatum. They are magnificent!
Friends from Czech told me about this population. C. guttatum is growing in fairly open Spruce/Quaking Aspen forest near Fairbanks Alaska. The trees were fairly sparse around the population. The slope was facing WNW, but others were growing on WSW-faicing slope, and plants were getting full sun exposure. Pretty healthy populations with lots of seed pots from last year (which can be seen in the photo). I also saw lots of flowering and juvenile plants. The soil is supposed to be eroded old calcareous rocks. They were growing along with some grass/sedge, Dryas octopetala, and other herbaceous plants typical of interior Alaska.
My seedlings from Spangle Creek Lab are still in the 2nd year after deflasking. It's going to take quite a few more years before flowering. It's kind of interesting that natural Cyp. guttatum is thriving in the soil which doesn't look so different from my backyard. But in cultivation, I'm using a completely different type of soil (mostly perlite).