Cypripedium parviflorum
yellow lady's slipper
North America (Canada and United States)
Overview
Cypripedium parviflorum is a hardy terrestrial orchid native to North America, forming clumps 6-28 inches (15-70 cm) tall from a slow-creeping rhizome. Each stem carries three to five pleated, oval leaves 2-8 inches (5-20 cm) long that clasp the stem, with one or two flowers held at the top. The flower has a pouch-shaped yellow lip 0.75-2 inches (2-5 cm) long, the slipper that gives the plant its name, framed by spirally twisted sepals and petals in greenish-yellow to brownish-purple. Plants grow in moist woodlands, fens, and shaded slopes, depending on an association with soil fungi that makes them slow to establish and difficult to transplant or grow from seed. Flowers open in late spring and last one to two weeks, drawing bees through scent and color though the flower produces no nectar. The species is long-lived where undisturbed, with clumps slowly enlarging over many years. Limitations include very slow growth, strict needs for humus-rich, well-drained soil and dappled shade, and glandular leaf hairs that can irritate skin. Wild collection has reduced many populations, so nursery-propagated plants are used in gardens rather than wild-dug stock. Foliage dies back to the ground each winter.
Native Range
Cypripedium parviflorum is native to North America, ranging across Canada and much of the United States from the East Coast to the Rocky Mountains. It grows in moist deciduous and mixed woodlands, fens, and shaded slopes with rich, humus-laden soil.Suggested Uses
Grown in shaded native plant and woodland gardens with rich, moist soil and dappled light. Suited to fern and wildflower plantings under deciduous trees. Used as a specimen in cool, humus-rich beds where it can remain undisturbed for years.How to Identify
Appearance
Size & Dimensions
Height6" - 2'4"
Width/Spread1' - 1'6"
Reaches mature size in approximately 5 years
Bloom Information
Flowers open in late spring, generally May into June depending on latitude and elevation. Each stem holds one or two blooms that last one to two weeks. The pouch-shaped yellow lip and twisted side segments are fully formed as the leaves expand. No repeat bloom follows in a season.
Detailed Descriptions
Flower Description
Yellow pouch with brownish-purple petalsFoliage Description
Green, pleatedGrowing Conditions
Sun Requirements
Requires 2-5 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight