Lady's Slipper

Pink Lady's Slipper Cypripedium acaule

Yellow Lady's Slipper Cypripedium calceolus

Pictures Taken May 12, 2000

The Pink Lady's Slipper is one of more than 50 species of orchids that can be found in North Carlina. These orchids grow mainly in low pinelands and bogs in the mountains and the coastal plain. The genus name, Cypridedium, is from the Greek for Venus's Slipper. The specific epithet, acaule, refers to the leafless stem that bears the flower.

As with most orchids, the Lady's Slipper flowers are modified to attract specific pollinators. The pollinators are medium-sized bees such as Mining bees of the genus Andrena. Once attracted to the flower by color and scent, the pollinator enters the inflated lower petal or sac through a one-way opening. After it is inside, it can exit only through one of two exit holes at the top of the sac. In exiting, it leaves behind pollen it has acquired from a previous orchid visit and it picks up pollen from this flower. The pathway taken by the pollinator assures cross-pollination. To improve chances that a flower will be visited by a pollinator, Lady's Slipper flowers usually last for several weeks. Yet, in many places, only about 10 percent of the plants set seed. Luckily, one capsule or fruit produces about 10,000 seeds. Click here for a picture of the seed pod, or go to the picture for June 11.

The tiny seed of orchids contains little or no food reserves for the embryo, unlike most seeds. In order for the seed to germinate and develop, it must become associated with certain fungi found in most soils. The fungus nourishes the developing seedling until finally, after two or three years, the plant has leaves large enough to sustain itself by photosynthesis. At this point, the seemingly ungrateful orchid will sometimes cast off its fungal partner.

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