Cypripedium

Slipper orchids
Showy lady slipper
(Cypripedium reginae)
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Cypripedioideae
Tribe: Cypripedieae
Subtribe: Cypripediinae
Genus: Cypripedium
L., 1753
Species

See text.

Cypripedium is a genus of 47 species of lady's-slipper orchids native to temperate and colder regions of the Northern Hemisphere.

Some grow in the tundra in Alaska and Siberia, which is an unusually cold habitat for orchids. They can withstand extreme cold, growing under the snow and blooming when the snow melts. But, in the wild, most have become rare and close to extinction, due to an ever shrinking natural habitat and overcollection. In the late 20th century, only a single plant of Cypripedium calceolus survived in Britain.

Common names include slipper orchid, lady's slipper, mocassin flower, camel's foot, squirrel foot, steeple cap, Venus' shoes and whippoorwill shoe. An abbreviation used in trade journals is 'Cyp'.

The genus has a long history of use, dating back 2500 years to the Far East, where they were used medicinally.

Contents

Characteristics

As with most terrestrial orchids, the rhizome is short and robust, growing in the uppermost soil layer. The rhizome grows annually with a growth bud at one end and dies off at the other end. The stem grows from the bud at the tip of the rhizome. Most slipper orchids have an elongate erect stem, with leaves growing along its length. But the Mocassin Flower (Cypripedium acaule) has a short underground stem with leaves springing from the soil. The often hairy leaves can vary from ovate to elliptic or lanceolate, folded along their length. The stems lack pseudobulbs.

The inflorescence is racemose. It can carry one to twelve flowers, as in Cypripedium californicum. But most species have one to three flowers. There are three sepals, with, in most species, the two lateral ones more or less fused. The flower has three acute petals with the third a striking slipper-shaped lip, which is lowermost. The sepals and the petals are usually similarly colored, with the lip in a different color. But variations on this theme occur. The aspect of the lip of different species can vary a great deal. As with all orchids, it is specially constructed to attract pollinators. The flowers show a column with a unique shieldlike staminode. The ovary is 3-locular (with three chambers).

Synonymy

The following genera have been brought into synonymy with Cypripedium:

Taxonomy

Comparison between a DNA-analysis and the morphological characteristics in this genus has shown that there is a high degree of divergence between the two, probably due to long periods of isolation or extinction of intermediate forms. The Eurasian species with yellow or red flowers form a distinct group from the North American species with yellow flowers. The Pelican Orchid (Cypripedium irapeanum) and the California Lady's Slipper (Cypripedium californicum) are probably the first diverging line. They share several similarities with their sister group Selenipedium.

Species and natural hybrids

There are approximately 356 species in this genus, including:

References

External links