Cypripedium acaule Aiton

Pink lady’s slipper, moccasin flower, lady’s slipper

About plant names...

These delicate North American natives, now considered endangered in Canada and rare or endangered in many parts of the United States, appear occasionally in the woods near our camp on Sebago Lake in Maine. As children, coming upon one in the woods was a magical experience. The flowers are stunningly beautiful, yet fragile looking. We knew they were rare and could not be transplanted. (Now botanists know that transplantation fails because lady’s slippers have a symbiotic relationship with a fungus in the soil.) We never dreamed of picking them or disturbing them. We simply admired them as they are and gave them a wide berth.

Plants: Plants consist of two long narrow leaves coming directly from the ground (basal), with a central flower stalk.

Leaves: The two dark green leaves are each about 6-12" (15-30 cm) long and 1-2" (2.5-5 cm) wide. They have parallel veins.

Flowers: A bare stalk supports a single delicate, pink, slipper-shaped flower, 1½-2" (3.8-5 cm) long and about ¾" (1.9 cm) around at its widest point. The color can range from nearly white to dark pink. There is an opening at the top of the flower, completing the resemblance to a slipper. (Cypripedium is Greek for “Aphrodite’s shoe.”) A “cap,” composed of a modified leaf and two sepals, appears over the flower.

Online References:

The Orchids Wiki

Earl J.S. Rook's Flora, Fauna, Earth, and Sky ... The Natural History of the Northwoods

The Orchids of Wisconsin

The Lady Bird Johnson Wildflower Center

Plants for a Future, a resource and information centre for edible and otherwise useful plants

The Connecticut Botanical Society's Connecticut wildflowers site

Wildflowers of the United States

EFloras

6/3/2018 · Mt. Watatic, Ashby, Mass­a­chu­setts
≈ 5 × 7" (13 × 17 cm)

6/1/2014 · Oak Hill, Littleton, Mass­a­chu­setts
≈ 8 × 6" (19 × 16 cm)

6/7/2014 · Beaver Brook Conservation Area, Hollis, New Hamp­shire
≈ 7 × 7" (17 × 18 cm)

5/28/2021 · Brunswick Commons, Brunswick, Maine
≈ 4 × 4½" (10 × 11 cm)

4/27/2010 · Nashua River Rail Trail, Pepperell, Mass­a­chu­setts
≈ 8 × 9" (19 × 22 cm) ID is uncertain

5/12/2016 · Wildlife Pond Trail, Beaver Broo, Hollis, New Hamp­shire

6/1/2014 · Oak Hill, Littleton, Mass­a­chu­setts
≈ 6 × 4½" (14 × 12 cm)

They aren't usually this pale-colored. · 5/28/2021 · Brunswick Commons, Brunswick, Maine
≈ 4 × 5" (10 × 13 cm)

5/16/2016 · Oak Hill, Littleton, Mass­a­chu­setts

5/24/2021 · Long Reach Preserve, Harpswell, Maine
≈ 4½ × 7" (11 × 16 cm)

5/26/2018 · Burge’s Pond, Westford, Mass­a­chu­setts
≈ 7 × 6" (18 × 16 cm)

5/21/2014 · Beaver Brook Assn Conservation Lands, Rte. 130, Hollis, New Hamp­shire
≈ 7 × 6" (17 × 16 cm)

Cypripedium acaule description by Thomas H. Kent, last updated 11 Jul 2023.

© FloraFinder.org. All rights reserved.

5/25/2023 · Maquoit Bay Conservation Land, Brunswick, Maine

5/28/2017 · Beaver Brook Conservation Area, Wildflower Trail, Hollis, New Hamp­shire
≈ 5 × 7" (13 × 18 cm)

5/28/2018 · Oak Hill, Littleton, Mass­a­chu­setts

6/8/2005

5/20/2021 · Eaton Farm Preserve, Wiscasset, Maine
≈ 4 × 4½" (10 × 12 cm)

5/13/2012 · Lowell-Dracut-Tyngsboro State Forest, Lowell, Mass­a­chu­setts

5/13/2012 · Lowell-Dracut-Tyngsboro State Forest, Lowell, Mass­a­chu­setts
≈ 7 × 8" (18 × 21 cm)

4/15/1979 · Memphis, Ten­nes­see · By Tim Chandler

6/8/1985 · Mackworth Island, Falmouth, Maine

5/5/2010 · Nashua River Rail Trail, Pepperell, Mass­a­chu­setts
≈ 3½ × 5" (9.2 × 13 cm)

5/28/2021 · Brunswick Commons, Brunswick, Maine
≈ 5 × 7" (13 × 16 cm)

12/8/2020 · Frenchman Bay Conservancy, Hancock County, Downeast, Maine · By Susan Cole Kelly

5/28/2021 · Brunswick Commons, Brunswick, Maine
≈ 4 × 6" (10 × 16 cm)

5/5/2010 · Nashua River Rail Trail, Pepperell, Mass­a­chu­setts
≈ 7 × 9" (19 × 22 cm)

Range:

About this map...