Cypripedium reginae Walter

Showy Lady's Slipper


CC = 10
CW = -3
MOC = 9

© SRTurner

Family - Orchidaceae

Habit - Rhizomatous perennial forb.

Stem - Ascending to erect, to 1 m, usually densely hairy and glandular, with 1 or 2 (3) flowers.

Cypripedium_reginae_stem.jpg Stem. The numerous glands impart a clammy feel to the foliage.

© SRTurner

Leaves - Alternate, simple, sessile, 3-10 per flowering stem, 15-25 cm long, more than 4 cm wide, ovate, the surfaces somewhat ribbed or corrugated and hairy.

Cypripedium_reginae_leaves1.jpg Stem and leaves.

© SRTurner

Cypripedium_reginae_leaf1.jpg Leaf adaxial.

© SRTurner

Cypripedium_reginae_leaf2.jpg Leaf abaxial.

© SRTurner

Inflorescence - Spikes with 1-3 flowers per stem, each flower subtended by a bract.

Flowers - Sepals 3.0-4.5 cm long, broadly elliptic, flat or slightly arching, white. Lateral petals 2.5-4.5 cm long, shorter than to about as long as the lip, oblong-elliptic, flat or slightly arching, not spirally twisted, white. Lip 3-5 cm long, enlarged to form an obovoid slipperlike pouch, the margins rolled inward along the edge of the opening, white, tinged with pink, the inside surface with reddish purple streaks. Column 15-25 mm long, the staminode ovate, white with red spots and yellow areas toward the margins.

Cypripedium_reginae_flowers.jpg Flowers.

© SRTurner

Cypripedium_reginae_flower1.jpg Bract and flower lateral view.

© SRTurner

Cypripedium_reginae_bract.jpg Bract.

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Cypripedium_reginae_flower2.jpg Flower.

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Cypripedium_reginae_interior.jpg Interior of lip.

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Fruit - Capsules borne erect or nearly so, 20-30 mm long, elliptic in outline, strongly ribbed.

Cypripedium_reginae_fruit.jpg Previous year's fruit.

© SRTurner

Flowering - May - June.

Habitat - Seepy ledges of sheltered, north-facing dolomite bluffs, less commonly along moist stream banks and in fens.

Origin - Native to the U.S.

Lookalikes - None when flowering. Vegetatively similar to other members of the genus.

Other info. - When flowering this plant is unmistakable, with a healthy specimen often bearing a dozen or more pink, slipper-shaped flowers. The species is most common in northeastern parts of the U.S. and also Canada. In Missouri it is uncommon, partly due to its strict habitat requirements and partly from unscrupulous poaching of plants from the wild. There is little purpose in attempting to transplant orchids from the wild into gardens. Their strict requirements of several habitat variables, including mycorrhizal soil associates, usually doom such endeavors.

Pollination in orchids of this genus involves insects becoming trapped in the pouchlike lip after being attracted by the scent and color of the flowers. These are false promises, as the flowers offer no nectar. The insects must escape through small orifices toward the rear of the pouch, which forces them to rub against the stamens. Not learning from the experience, the insects repeat their mistake with another flower, thus transferring the pollen.

Photographs taken in Missouri.