Cypripedium passerinum

Cypripedium passerinum
Conservation status
Apparently Secure (NatureServe)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
Order:	Asparagales
Family:	Orchidaceae
Subfamily:	Cypripedioideae
Genus:	Cypripedium
Species:	C. passerinum
Binomial name
Cypripedium passerinum Richardson

Cypripedium passerinum is a species of lady's slipper orchid^[1] known by the common names sparrow's-egg lady's-slipper, spotted lady's-slipper, and Franklin's lady's-slipper. It is native to northern North America, where it occurs in Alaska and much of western and central Canada, its distribution extending to Quebec. Its range extends as far south as Glacier National Park in Montana.^[2]

This orchid is a rhizomatous perennial herb growing to a maximum height around 50 centimetres (20 inches). There are 3 to 7 oval or lance-shaped leaves arranged alternately on the stem, each up to 19 centimetres (7.5 inches) long by 6 cm (2.4 in) wide. The herbage is hairy and sticky.^[3] The inflorescence at the top of the stem contains one or two flowers. The flower has a dorsal sepal covering the petals and two lateral sepals. There are three petals: two flat white petals on either side and one central petal modified into a white or pink-tinged pouch with purplish spotting at the lip and inside, which is said to resemble a sparrow's egg.^[1] The fruit is a capsule. The plant may reproduce by seed but it more often reproduces vegetatively by sending up more stems from the rhizome.^[2][4]

This species grows farther north than other Cypripedium.^[1] It grows in moist spruce forests at low elevations, tundra, dunes, and river terraces, lakeshores, and streambanks.^[2][4] It often grows on calcareous substrates. It is associated with plants such as white spruce (Picea glauca), Engelmann spruce (P. engelmannii), western redcedar (Thuja occidentalis), red-osier dogwood (Cornus sericea), willows (Salix spp.), horsetail (Equisetum spp.), longtube twinflower (Linnaea borealis), sedges (Carex spp.), one-sided pyrola (Pyrola secunda), and moss carpet (Pleurozium schreberi).^[2]

References

1. ^ ^{a b c} Cypripedium passerinum. Meet The Ladies: The Slipper Orchids. Celebrating Wildflowers. USFS. Retrieved 11-14-2011.
2. ^ ^{a b c d} Williams, Tara Y. 1990. Cypripedium passerinum. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. Retrieved 11-14-2011.
3. ^ Cypripedium passerinum. The Nature Conservancy. Retrieved 11-14-2011.
4. ^ ^{a b} Cypripedium passerinum. Flora of North America. Retrieved 11-14-2011.

External links

• USDA Plants Profile