Common Name: Sparrow's-egg Lady's-slipper

General Information

Cypripedium passerinum is a herbaceous perennial plant producing a cluster of stems from its rootstock. Each erect stem bears 3 - 7 leaves and is usually 12 - 38cm tall, occasionally reaching 50cm[, ].
The plant is harvested from the wild for its root, which is used medicinally. It is also grown as an ornamental[].
Cypripedium passerinum is common to occasional in suitable habitats and rare in other parts of its range. The trend of the population is decreasing slowly and the total mature individuals varies between 1,200 to 10,000 individuals with extreme fluctuations. The habitats are under numerous threats especially overgrazing, livestock grazing, recreational activities, clear-cutting, deforestation, fires, timber harvesting and collection from the wild for horticultural or medicinal purposes, which cause a continuing decline of the species and the destruction of some subpopulations. The plant is classified as 'Vulnerable' in the IUCN Red List of Threatened Species(2014)[].

Known Hazards

We have no specific reports for this species but, especially during the flowering season, the glandular hairs on the leaves and stems of some N. American members of this genus can cause a rash, similar to poison ivy rash[, ]. The irritation is usually minor, or only lasts for a few minutes[].
We have no specific information for this species, but it has been stated that the roots of at least one member of the genus may cause psychedelic reactions, and large doses may result in giddiness, restlessness, headache, mental excitement and visual hallucinations[].

Botanical References

Range

Northern and central N. America - Alaska to Nunavut, south to British Colombia, Mintana, Ontario and Quebec

Habitat

Moist coniferous forests, thickets, openings, tundra, especially in coarse soils of terraces and stream banks; at elevations up to 2,200 metres[].

Properties

Conservation Status	Vulnerable
Medicinal Rating
Habit	Perennial
Height	0.25 m
Pollinators	Bees, Insects
Self-fertile	Yes
Cultivation Status	Ornamental, Wild

Cultivation Details

Cypripedium passerinum is a very cold-tolerant plant, when fully dormant it can withstand temperatures down to about -35°c[].
Prefers a position in bright light on a well-drained slope[]. Found in the wild on moist to dry substrates especially coarse soil of terraces, rich in humus and neutral to acidic calcareous substrates[].
Orchids are, in general, shallow-rooting plants of well-drained low-fertility soils. Their symbiotic relationship with a fungus in the soil allows them to obtain sufficient nutrients and be able to compete successfully with other plants. They are very sensitive to the addition of fertilizers or fungicides since these can harm the symbiotic fungus and thus kill the orchid[].
The flowers of Cypripedium species belong to the group of 'trap' flowers. An insect as it crawls in, can only escape from the slipper-like labellum through a tunnel near the base of the labellum from where it is directed first to the nearby stigma where possible pollinia from another flower on its back are stripped off and while escaping, sticky pollen from the nearby anthers adhere to its back for the pollination of another flower[].

Edible Uses

None known

Medicinal

Cypripedin, a powder produced by precipitating a tincture of the root with water, was thought to have greater powers than the root and was given to children instead of opium[].
An extract from the roots of this species was used historically as a sedative and treatment for nervous disorders or antispasmodic and cure for insomnia[].
The species is also taken in a sweetened concoction to treat headaches[].

Other Uses

None known

Propagation

Seed - surface sow, preferably as soon as it is ripe, in the greenhouse and do not allow the compost to dry out. The seed of this species is extremely simple, it has a minute embryo surrounded by a single layer of protective cells. It contains very little food reserves and depends upon a symbiotic relationship with a species of soil-dwelling fungus. The fungal hyphae invade the seed and enter the cells of the embryo. The orchid soon begins to digest the fungal tissue and this acts as a food supply for the plant until it is able to obtain nutrients from decaying material in the soil[]. It is best to use some of the soil that is growing around established plants in order to introduce the fungus, or to sow the seed around a plant of the same species and allow the seedlings to grow on until they are large enough to move.
Division with care in early spring, the plants resent disturbance[]. Remove part of the original rootball, making sure to keep some of the soil around it intact[].
Division is best carried out towards the end of the growing season, since food reserves are fairly evenly distributed through the rhizome[]. Small divisions of a lead and two buds, or divisions from the back (older) part of the rhizome without any developed buds, establish quickly using this method[]. Replant immediately in situ[].