Cypripedium parviflorum var. pubescens (Greater Yellow Lady's-slipper)
|Also known as:
|Large Yellow Lady's Slipper
|shade, sun; moist rich woods, bogs, swamps
|May - July
|8 to 30 inches
|Wetland Indicator Status:
|GP: FACW MW: FACW NCNE: FAC
|MN county distribution (click map to enlarge):
|National distribution (click map to enlarge):
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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. Lateral petals are narrow, up to 2 inches long, typically spirally twisted, typically greenish to yellowish and flecked with purplish striping. Sepals are similar in color, 2 are fused behind the lip; upper sepal is broader and is erect above the lip. A single leaf-like, sparsely hairy floral bract stands erect at the top of the stem, behind the ovary. A 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.
Fruit is an oblong-elliptic capsule containing numerous tiny seeds.
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.
Where Cypripedium candidum (Small White Lady's-slipper) and C. parviflorum (either or both vars) are in close proximity to each other, such as the edge where prairie meets forest, hybrids are likely to occur; the hybrid between C. candidum and C. parviflorum var. makasin is known as C. ×andrewsii. According to Welby Smith's book “Native Orchids of Minnesota”, the hybrids can be baffling, most with intermediate characteristics in flower size and color, but some with different traits of each parent. In each case, the flower color may be white, creamy or yellow. It also mentions a study in Iowa showed hybridization was more common than previously thought, the hybrids cross-breeding between themselves and their parents, known as a hybrid swarm.
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- Greater Yellow Lady's Slipper plant, about 18 inches tall
- a flower just starting to bloom
- more plants
- Cypripedium candidum, C. parviflorum, and hybrid C. X andrewsii
Photos by K. Chayka taken at Wild River State Park, Center City, MN May 2009. Photo by Derek Anderson taken in Mahnomen County.
Have you seen this plant in Minnesota, or have any other comments about it?