showy lady's slipper

Like other lady's slipper orchids (subfamily Cypripedioideae) the Cypripedium reginae has flowers with a pouch-shaped labellum. Cypripedium reginae is a large, terrestrial orchid, growing 21–100 cm (0.7–3 ft) in height with many stems from the same rootstock. Each stem has three to five alternate, pubescent leaves. Each ovately shaped leaf grows up to 25 cm (10 in) long and 16 cm (6 in) broad. Flowering stems one to three large, white and pink flowers. The upper petals are white, up to 4 cm (2 in) in length and 1.5 cm (0.59 in) across. The pouch-shaped labellum is rose-pink to magenta 2.5–5.5 cm (0.98–2.17 in) in length. Despite producing a large amount of seeds per seed pod, it reproduces largely by vegetative reproduction.

Cypripedium reginae grows in wetlands such as fens, wooded swamps, and riverbanks. Cyp. reginae thrives in neutral to basic soils but can be found in slightly acidic conditions. The plants often form in clumps by branching of the underground rhizomes. Its roots are typically within a few inches of the top of the soil. It prefers very loose soils and when growing in fens it will most often be found in mossy hummocks. It can tolerate full sun but prefers partial shade for some part of the day. When exposed to full sun, the flower lip is somewhat bleached and less deeply colored. It is occasionally eaten by white-tailed deer. Cypripedium reginae can be found in Canada from Saskatchewan east to Atlantic Canada, and the United States from North Dakota east to the Atlantic and south to Arkansas and Tennessee.

Cypripedium reginae reproduces sexually and depends on insects such as syrphid flies, beetles and Megachile bees for pollination. The structure of the flower creates a tight space through which insects have to squeeze. A pollinating insect first passes by the stigma, and upon exiting the trap rubs against the anther. Pollination typically occurs in June and the seed pod or fruit is ripe by September and dehisces by October. Although a single seed pod can produce over 50,000 seeds, low germination and a seed-to-flowering term of about eight years indicate that sexual reproduction is inefficient. Asexual reproduction from rhizomes is a common means of sustaining a population. It flowers in early to midsummer, usually with 1 to 2 flowers per stalk, less commonly 3 or 4.

The Cypripedium species have been used in native remedies for dermatitis, tooth aches, anxiety, headaches, as an antispasmodic, stimulant and sedative, but the preferred species for these uses are Cypripedium parviflorum and Cypripedium acaule, used as topical applications or tea.

The showy lady's slipper has been a subject of horticultural interest for many years, and was known to Charles Darwin who, like many, was unsuccessful in cultivating the plant. It has low seed germination rates and slow maturation to flowering. This makes it more vulnerable to illegal collection. It was historically difficult to raise from seed in sterile culture or in greenhouse conditions, taking many months to germinate in sterile culture. In the 1990s a group of high school students in New Hampshire, under the direction of Dr. Peter Faletra, made substantial progress on axenic culture from seed and were able to obtain over 50% germination levels in about 3 weeks. Efforts at micropropagation have had marginal success. Methods on transplanting seedlings raised in axenic culture to artificial fens have been advanced by The New Hampshire Academy of Science and can be found at the website [1].

The species name reginae is Latin for "of a queen". Common names also include fairy queen, white wing moccasin, royal lady's slipper, and silver-slipper.