Calypso Orchid (Fairy Slipper) Plant Profile

The calypso plant, though tricky to cultivate, is beautiful when in bloom. Calypso © Hofmann/Flickr
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The rare and beautiful calypso orchid is classified as a monotype genus, meaning it comprises only one species: Calypso bulbosa, This small and easily damaged plant can feature subtle purple colorations and a wide variety of patterns on its single cup-shaped flower. Often very small, Calypso plants are found naturally in forests all over the world, distributed over several continents. But despite their wide range, they’re very often disturbed and are considered threatened in many areas, including in several U.S. states.

Unfortunately, this plant is not commonly sold commercially, either in seed or plant form, and it may be impossible to find. This means you'll have to be satisfied with enjoying it in the wild. Of course, for any orchid lover, a natural encounter with a rare species is the best reward of all.

Typically, calypso blooms range from purple to pink to red, though they often have tinges of yellow as well. There are two varieties in North America, which can be identified by the color of their labellum: americana (pink or white labellum) and occidentalis (white labellum with red markings).

They are forest plants that grow naturally underneath the canopies of trees. It’s from this growth habit that they get their name; “calypso” refers to concealment, as these plants grow on the floor and can be difficult to spot. Calypso is also the mythological sea nymph in Homer's Odyssey who attempts to keep Odysseus as her captive husband. Fairy slipper orchids are very difficult to cultivate partly because they must be grown in contact with fungi, specifically Thanatephorus ochraceus, from which it extracts carbon.

Botanical Name Calypso bulbosa
Common Name  Calypso orchid, fairy slipper, Venus' slipper, angel slipper
Plant Type  Perennial
Mature Size  3 to 6 inches tall, 3 inches wide
Sun Exposure Part shade, shade
Soil Type  Soil with moist duff or moss
Soil pH  Neutral to alkaline (up to 7.2)
Bloom Time  Spring, summer
Flower Color  White, magenta, pink to red
Hardiness Zones 4 to 8 (USDA)
Native Area  North America, Eurasia 
Toxicity N/A

Calypso Orchid Growing Conditions

Light

Calypso orchids grow underneath other structures and therefore partial shade or filtered sunlight is best. Too much light can scorch their leaves and cause discoloration.

Soil

These flowers are typically found in coniferous forests, growing in moist soil with a thick layer of duff or moss.

Water

The tiny calypso orchid draws the water it needs from moist soil.

Temperature and Humidity

Warm to moderate temperatures are ideal, but this is a hardy forest plant that can tolerate wide swings in temperature. It thrives in a variety of ecosystems, including forests, bogs, woodlands, floodplains, and swamps.

Calypso Orchid Varieties

  • C. bulbosa var. bulbosa: The first Calypso bulbosa variety to be identified botanically, in 1753; found in Europe and Asia, from Scandinavia and Russia to Korea and Japan
  • C. bulbosa var. speciosa: A high-altitude variety found in elevations up to 10,500 feet, primarily in subalpine forests of China and Japan as well as inner Mongolia
  • C. bulbosa var. americana: One of two varieties found in North America, including Canada, the northern U.S. states, and in Wyoming, Colorado, New Mexico, Arizona, Utah, and Alaska
  • C. bulbosa var. occidentalis: The other North American variety, found along the west coast and in Idaho, Montana, and Alaska in the U.S. as well as British Columbia

Calypso Orchid Life Cycle

As a monoecious plant, the calypso orchid cannot self-pollinate. It relies on bees for pollination. The plant grows each year as a new shoot that sprouts from an underground corm (rhizome). The base of the shoot becomes a new part of the corm, and older growth of the corm remains attached for two to four years. Mature plants bear one leaf and a single flower that blooms, typically, in late spring. The leaf is deciduous but often stays on the plant through the winter and falls off the following summer.