Northern Prairie Wildlife Research Center
Northeast Wetland Flora
Field Office Guide to Plant Species
Cypripedium reginae Walter
- Family: Orchid (Orchidaceae)
- Flowering: May-August
- Field Marks: This lady's-slipper differs by its white sepals and petals and its white lip often
tinged with pink or rose.
- Habitat: Bogs, fens, swamps.
- Habit: Perennial herb with thick, fibrous roots.
- Stems: Upright, unbranched, up to 2 1/2 feet tall, with short, stiff, spreading hairs, bearing
- Leaves: Several, alternate, broadly elliptic to ovate, short-pointed at the tip, up to 1 foot
long, up to 6 inches wide, hairy, strongly veiny.
- Flowers: 1-3 borne at the tip of a leafy stem, up to 2 1/4 inches long, subtended by a leaf-like bract up to 3 inches long.
- Sepals: 3, united, unlike, white, waxy, rounded at the tip, the upper one nearly spherical,
up to 2 1/2 inches long, at maturity arching over the lip, the other 2 narrower.
- Petals: 3, unequal, the lateral 2 white, rounded at the tip, oblong, flat, up to 1 3/4 inches long;
lip petal pouch-shaped, white but strongly marked with pink or rose, 1 1/4-2 1/4 inches long.
- Stamens: 2.
- Pistils: Ovary inferior.
- Fruits: Capsule ellipsoid, up to 2 1/4 inches long.
- Notes: The hairs of the fresh foliage may cause serious eczema.
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