Venus's Slipper

Family Orchidaceae. The genus was given the name 'slipper' because the lip's shape resembles a woman's slipper. In most European languages, as in Latin, this genus is called lady's slipper, Venus's slipper, lady's shoe, etc.

The genus lady's slipper, or Venus's slipper, includes about 50 species distributed in South and North America, Europe and Asia, from the forest-tundra to the tropics.

Plants with a rhizome, a glandular-hairy stem and large leaves. The stem is either very short, in which case there is a single pair of leaves that appear basal and a single-flowered scape, or fairly tall, with large alternate leaves and usually several, more often 1–3, less often 6–12 flowers.

Flowers are fairly large, of peculiar shape, mostly brightly colored, typically with a vanilla scent. Bracts are also large and leaf-like. Sepals are petaloid; the upper one is ovate or elliptic; the two lateral ones often fuse into a single two-toothed structure at the tip, directed downward. Petals are elliptic or lanceolate, hanging at the sides of the lip, sometimes more or less twisted, often colored the same as the sepals. The lip is slipper-shaped, brightly colored, variously inflated, sometimes with a deep longitudinal fold, as if longitudinally split or compressed in front or on the sides, with an opening or mouth at the top. The column is fused with the staminode, on both sides of which are the anthers of two developed stamens. The stigma is shield-shaped, three-lobed or triangular, turned downward into the cavity of the slipper-shaped lip. The ovary is usually not twisted, generally on a short stalk. Flowers are pollinated by bees.

The flowers of lady's slippers with their complex structure are a typical example of "trap-flowers." Once inside the flower, pollinators — usually flying insects — can leave only by a specific route that ensures pollination. The insect is attracted by the bright color of the flower. It lands on the smooth edge of the lip, slips along it and falls into its cavity. After futile attempts to climb up the smooth, concave surface, the insect notices light coming from two apparent openings on the side walls at the base of the lip. Moving toward the light source, the insect must crawl past the flower's stigma, where the pollen it carries will be deposited, and only then can it find the real exit. Before leaving the flower, it will brush against an anther and sticky pollen grains (not united into pollinia) will adhere to its body. On entering another flower, the insect first touches the low-tilted stigma and fertilizes the flower, and only afterward the anther will dust it with a new load of pollen.

The most ancient and primitive orchid genus. In plants of this genus, instead of the single stamen retained by almost all orchids, two stamens function, and only the third, underdeveloped, has become a petaloid staminode. Pollen grains are not united into pollinia, but are grouped in fours and immersed in a sticky mass.

The development of lady's slipper seedlings from seed germination to the first flowering takes about 9–10, and often even 13–15 years. Plants can also be propagated vegetatively by successive division of the rhizomes. Mature lady's slippers are not overly dependent on mycorrhiza, and therefore they can be transplanted and grown in cultivation relatively easily.

Because vegetative propagation is ineffective, and growing seedlings in sterile test-tube conditions has so far not been successful, the natural habitats of the attractive species are being plundered worldwide. Today the list of species grown in cultivation includes cypripedium calceolus (С. calceolus) and c. macranthum (С. macranthum), as well as North American species: c. reginae (С. reginae), c. parviflorum (С. parviflorum), c. acaule (С. acaule) and c. arietinum (С. arietinum); Japanese species: c. debile (С. debile) and c. japonicum (С. japonicum); and, finally, the Himalayan c. cordigerum (С. cordigerum). New species of lady's slippers continue to appear, for example a miniature single-leaved species that has been imported from China several times in recent years.

Lady's slippers do not have a narrow ecological specialization, and therefore they can inhabit various biotopes, including open deciduous, mixed and coniferous forests, shrub and rocky slopes, as well as meadows and heaths high in the mountains and in lowlands. Since they inhabit only temperate zones of the Northern Hemisphere, they mainly flower from May to July.