Northern Prairie Wildlife Research Center
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.
Previous Section -- Coeloglossum viride (L.) Hartman
-- Long-bracted orchid
Return to Family -- Orchidaceae - The
Orchid Family
Next Section -- Cypripedium candidum Muhl. --
White ladyslipper
U.S. Department of the Interior |
U.S. Geological Survey
