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Northern Prairie Wildlife Research Center

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Aquatic and Wetland Vascular Plants of the Northern Great Plains

69. Orchidaceae, the Orchid Family

2. Cypripedium L. -- Ladyslipper

1. Cypripedium calceolus L. -- Yellow ladyslipper

Stems 1.5-6 dm tall, pubescent, the hairs often glandular. Leaves ascending, sheathing at the base, elliptic, 5-18 cm long, 2-7 cm wide, acute to acuminate, sparsely pubescent. Flowers 1 per stem or less often 2, each subtended by an erect leaflike bract 2.5-6 cm long; sepals and lateral petals greenish-yellow to purplish-brown, sepals 2-6 cm long, the upper sepal lanceolate to ovate-lanceolate, acuminate, the lateral sepals connate below the lip, lanceolate, bidentate at the tip; lateral petals lanceolate to linear-lanceolate, acute to attenuate, usually twisted 1-several times, 2-5 cm long; lip yellow, often purple-veined and purplish-dotted around the orifice, 1.5-4 cm long; ovary strongly glandular-pubescent, 1.5-3 cm long. Jun--Jul. Wet meadows, bogs, swampy areas and moist forest; rare from nc and e ND to extreme e NE, also the Black Hills; (Circumboreal, in N.Amer. from N.S. to AK, s to GA, AL, TX, NM, UT and OR). C. parviflorum Salisb.

In North America, C. calceolus has been divided into two main varieties (formerly considered separate species) on the basis of the lip size. In the e U.S., the prevailing form is var. pubescens (Willd.) Correll, in which the lip averages 3-6 cm long. The western form is var. parviflorum (Salisb.) Fern., distinguished by a lip averaging 2-3 cm long. In this region, specimens referable to both varieties are encountered, as well as intermediates which are difficult to assign to either variety.

GIF- Species Photo/Drawing
Cypripedium calceolus.
GIF- Distribution Map

Map key

Previous Section -- Coeloglossum viride (L.) Hartman -- Long-bracted orchid
Return to Family -- Orchidaceae - The Orchid Family
Next Section -- Cypripedium candidum Muhl. -- White ladyslipper

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