Flower:

Flower is irregular with a yellow pouch-shaped lower lip up to 2 inches long and a V-shaped column above the mouth of the pouch. The column and rim of the mouth are usually covered in reddish spots or stripes and there may be faint stripes on the sides and bottom of the pouch. What appears to be 4 or 5 narrow petals, each up to 3 inches long, are striped or spotted greenish brown and twisted to varying degrees; usually 1 is erect and 1 spreads out at each side. One plant typically has a single flower, occasionally 2.

Leaves and stem:

3 to 6 leaves are alternately attached up the stem. Leaves are up to 7 inches long and 4 inches wide, generally oval, toothless, pointed at the tip, tapering towards the base, clasping the main stem. There are many deep parallel veins that give it a striped look. The leaves and stem of young plants are noticeably hairy but may become less so with age.

Notes:

This is the most common wild orchid in the U.S. and is found in almost every state. There are 3 accepted varieties of Yellow Lady's Slipper, 2 of which are found in Minnesota: Greater Yellow Lady's Slipper (var. pubescens) and Small Yellow Lady's Slipper (var. makasin). The flower pouch of Small is only up to about 1 inch long, the petals are usually darker in color and more twisted than the Greater variety, but the Greater variety can be variable in these things depending on environmental conditions. All 3 sub-species (including var. parviflorum) go by mulitple variations on their scientific names. At one time these North American orchids were considered the same as the European species (Cypripedium calceolus) but not any longer.