Cypripedium montanum is a member of the orchid genus Cypripedium. It is commonly known as the Large Lady's Slipper, Mountain Lady's Slipper, White Lady's Slipper as well as Moccasin Flower. This latter is also the common name of Cypripedium acaule.
C. montanum, sometimes called "Mountain Lady's Slipper," grows to be up to 70 cm tall. The stem has alternating, plicate leaves. Atop the stem sits one to three large flowers. The sepals and petals tend to be maroon-brown while the pouch is white. This species is a close ally of Cypripedium parviflorum, so they appear to be very similar with the main difference being pouch color.
C. montanum can be found along the western third of the United States and Canada, from California and Colorado all the way up to Alaska. It is usually found at high elevation in open woods and subalpine slopes.