Burke: Cypripedium montanum vs. Cypripedium parviflorum

	Cypripedium montanum	Cypripedium parviflorum
	mountain lady's-slipper	yellow lady's-slipper
Habit	Glandular-pubescent, perennial herbs, the stems 2-6 dm. tall, leafy throughout.	Sparsely pubescent, perennial herbs, the stems 1.5-4 dm. tall, glandular, leafy throughout.
Leaves	Leaves alternate, broadly elliptic to ovate-elliptic, 5-15 cm. long and up to 7 cm. broad, sessile and sheathing.	Leaves alternate, broadly elliptic to elliptic-lanceolate, 6-17 cm. long and up to 7 cm. wide, sessile and slightly sheathing.
Flowers	Flowers 1-3 near the tip of the stem, each subtended and usually exceeded by an erect leaf-like bract; sepals and petals light to deep brownish-purple, narrowly to broadly lanceolate, the upper sepal 4-5 cm. long, the lower pair shorter, fused nearly to the tip; 2 small petals spreading, up to 6.5 cm. long; the third petal (lip) pouch-like, obovoid, 2-3 cm. long, dull white, usually purplish-veined; fertile stamens 2, the third stamen sterile and petal-like, up to 10 mm. long, ovate, yellowish-white and purple-spotted.	Flower solitary, terminal, subtended and usually exceeded by an erect, leaf-like bract; sepals and petals greenish-yellow to purplish-brown, wavy-margined, the upper sepal the largest, 2.5-4 cm. long, the lower pair completely fused; 2 small petals narrower and longer than the sepals; the third petal (lip) pouch-like, 2-3 cm. long, yellow, often purplish-dotted around the orifice; fertile stamens 2, the third sterile stamen petal-like, up to 10 mm. long, triangular, lobed at the base.
Fruits	Capsule.	Capsule.

	Cypripedium montanum	Cypripedium parviflorum
Flowering time	May-July	May-June
Habitat	Dry to moist open woods, low to mid-elevations in the mountains.	Fens, wetlands, shorelines, and damp woodlands, often where calcareous.
Distribution	Occurring east of the Cascades crest in Washington; Alaska to California, east to Montana and Wyoming. [WildflowerSearch map] [BONAP county map]	Occurring east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains; throughout most of Canada and the central, southeastern, and northeastern regions of the U.S. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Sensitive in Washington (WANHP)
Sibling taxa	C. ×columbianum, C. fasciculatum, C. parviflorum	C. ×columbianum, C. fasciculatum, C. montanum
Subordinate taxa		C. parviflorum var. makasin, C. parviflorum var. pubescens
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Cypripedium parviflorum

mountain lady's-slipper

yellow lady's-slipper

Habit

Glandular-pubescent, perennial herbs, the stems 2-6 dm. tall, leafy throughout.

Sparsely pubescent, perennial herbs, the stems 1.5-4 dm. tall, glandular, leafy throughout.

Leaves

Leaves alternate, broadly elliptic to ovate-elliptic, 5-15 cm. long and up to 7 cm. broad, sessile and sheathing.

Leaves alternate, broadly elliptic to elliptic-lanceolate, 6-17 cm. long and up to 7 cm. wide, sessile and slightly sheathing.

Flowers

Flowers 1-3 near the tip of the stem, each subtended and usually exceeded by an erect leaf-like bract;

sepals and petals light to deep brownish-purple, narrowly to broadly lanceolate, the upper sepal 4-5 cm. long, the lower pair shorter, fused nearly to the tip; 2 small petals spreading, up to 6.5 cm. long; the third petal (lip) pouch-like, obovoid, 2-3 cm. long, dull white, usually purplish-veined;

fertile stamens 2, the third stamen sterile and petal-like, up to 10 mm. long, ovate, yellowish-white and purple-spotted.

Flower solitary, terminal, subtended and usually exceeded by an erect, leaf-like bract;

sepals and petals greenish-yellow to purplish-brown, wavy-margined, the upper sepal the largest, 2.5-4 cm. long, the lower pair completely fused; 2 small petals narrower and longer than the sepals; the third petal (lip) pouch-like, 2-3 cm. long, yellow, often purplish-dotted around the orifice;

fertile stamens 2, the third sterile stamen petal-like, up to 10 mm. long, triangular, lobed at the base.

Fruits

Capsule.

Cypripedium montanum

Cypripedium parviflorum

Flowering time

May-July

May-June

Habitat

Dry to moist open woods, low to mid-elevations in the mountains.

Fens, wetlands, shorelines, and damp woodlands, often where calcareous.

Distribution

Occurring east of the Cascades crest in Washington; Alaska to California, east to Montana and Wyoming.

[WildflowerSearch map]

[BONAP county map]

Occurring east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains; throughout most of Canada and the central, southeastern, and northeastern regions of the U.S.

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sensitive in Washington (WANHP)

Sibling taxa

C. ×columbianum, C. fasciculatum, C. parviflorum

C. ×columbianum, C. fasciculatum, C. montanum

Subordinate taxa

C. parviflorum var. makasin, C. parviflorum var. pubescens