Pink Lady’s Slipper: Orchid on the Margins

By Ethan Hatchett

In early 2022, the Georgia Department of Transportation reported to DNR that land marked for a construction project along Ga. 400 in urban Alpharetta was home to over a thousand pink lady’s slipper orchids. DNR botanists investigated and decided to move the plants because a loss of that many orchids would significantly impact the species in the state.

Yet moving these delicate plants is not as simple as you might think.

Pink lady’s slippers are ground orchids known for their distinct and showy flowers. The plant grows in upland pine and mixed pine-hardwood forests with acidic soils. In the mountains, lady’s slippers occur near the edges of rhododendron thickets and mountain bogs. The species is found throughout Georgia’s Piedmont and mountain regions.

Moving a pink lady’s slipper is complicated. The state-protected orchids have a strong symbiotic relationship to a fungus of the Rhizoctonia genus in the soil. The plant’s roots combine with fungal tissue to benefit both orchid and fungus. As a result, pink lady’s slippers flourish and will eventually perish if this fungus is not present.

Botanists try to preserve this delicate fungal relationship by bringing topsoil from around each lady’s slipper to the relocation site. While this greatly increases the chances for survival, there’s no guarantee transplants will succeed. And orchids planted in a place where their symbiotic fungus is not present do not survive for long.

Tricky Pollination

The flower of the pink lady’s slipper (Alan Cressler)

Also, without human involvement, the pink lady’s slipper reproduces at a slow rate. The distinctive, slipper-shaped, hollow pouch formed by the lower petals is the most eye-catching feature of the orchid’s flower. Yet this unique feature also poses challenges to pollination.

Bees, the pink lady’s slipper’s main pollinator, learn to avoid the flower because of the orchid’s complex way of pollination. Bees enter the pouch of the flower through a one-way opening. The insects quickly discover that the plant produces no nectar: It has an inaccessible pollen packet the bee cannot use. There also is no ready way to escape: The bees can exit the flower only through two openings at the back of the lip.

While inside the flower, the plant’s pollen sticks to the bee’s back, where the insect is unable to reach or remove it. When the bee exits through one of the openings, it takes pollen from that orchid to be deposited in the next one. But because these insects rarely fall for the same trick twice, fewer flowers are pollinated.

Threats to Survival

Due to the orchid’s special requirements for survival, whole populations can perish when the habitat is disturbed by clearcutting and development. Many populations around metro Atlanta have been destroyed.

Encroachment from exotic invasive plants also has affected the pink lady’s slipper. These non-native plants crowd out the orchid’s habitat, undercutting its chances for survival.

Poaching poses a serious threat, as well. Pink lady’s slippers are dug up and sold, an illegal practice that can wipe out populations. These orchids can be bought commercially, but care should be taken not to purchase poached plants.

A New Start

Fortunately, the pink lady’s slippers along Ga. 400 in Alpharetta received a second chance on protected sites.

Volunteers from the Georgia Native Plant Society helped DNR remove and transplant the orchids to safer locations across the state. At the University of North Georgia, for example, botany students planted relocated orchids on university land.

The pink lady’s slipper is an interesting example of a protected plant that is not necessarily rare. The orchid can be found in relative abundance and has been observed in almost all northern counties in Georgia.

DNR botany technician Amaad Blades demonstrates how to plant a pink lady’s slipper for UNG students. (Ethan Hatchett/ DNR)

As development increases, however, the pink lady’s slipper is pushed farther to the margins of available habitat. The strict habitat requirements of the orchid restrict the number of places it can be successfully transplanted, adding to the challenge of conserving the species.

Yet as long as there are people watching over places for them to thrive, this orchid will continue to light up Georgia’s spring landscape.

Ethan Hatchett is a communications assistant in DNR’s Wildlife Conservation Section.

Top: A volunteer shows the root system of a dormant pink lady’s slipper. (Ethan Hatchett/DNR)