This section is from the book "Nature's Garden", by Neltje Blanchan. Also available from Amazon: Nature's Garden; An Aid To Knowledge Of Our Wild Flowers And Their Insect Visitors.
Flowers - Usually solitary, at summit of stem, white, the much inflated lip painted with purplish pink and white stripes; sepals rounded oval, spreading, white, not longer than the lip; petals narrower, white; the broad sac-shaped pouch open in front, 1 in. long or over. Stem: Stout, leafy, 1 to2 ft. high.
Leaves: 3 to 8 in. long, downy, elliptic, pointed, many ribbed. Preferred Habitat - Peat-bogs; rich, low, wet woods. Flowering Season - June - September. Distribution - Nova Scotia to Georgia, westward to the Mississippi.