Dragon’s mouth orchid, like several other orchid species, is subject to mutations in flower colour (including the lack of pigmentation). The pink-coloured flowers in the second photograph have the typical colouration.
These photographs were taken in early July in Newfoundland by UBC’s Curator of the E.H. Lohbrunner Alpine Garden, Laura Caddy. Laura was attending the 2018 annual meeting of the North American Rock Garden Society (you can see more photographs by visiting the NARGS Facebook page).
Arethusa bulbosa is native to eastern North America (northeastern USA and eastern Canada). The southern limit (North Carolina) and western limit (Saskatchewan) of its range are both populations that are disjunct from the core range by several hundred kilometres. Habitats, as noted by the Flora of North America, include: “Sphagnum bogs, coniferous swamps, calcareous treed to open fens, and moist, acid, sandy meadows” from sea level to 1100m (3600 ft.). Although considered a species of Least Concern in some jurisdictions, it bears some sort of official conservation status. One of the conservation challenges is its desirability to collectors, as it is considered by some to be among the most beautiful of flowers (though transplant is rarely, if ever, successful).
The North American Orchid Center has additional facts on Arethusa bulbosa, along with a half-dozen or so additional images.