Plant of the Week
Showy Lady’s Slipper (Cypripedium reginae)
By Wayne Owen
Showy lady’s slippers are the tallest native northern orchid, and many believe they are the most stunning. The specific epithet reginae is the Latin meaning "queen", and once seen in the wild, it is easy to understand why. Plants consist of a stout, hairy, leafy stalk usually bearing one large flower (or up to three). The flower is six-parted, with a pouch, or labellum, that’s one to two inches long, spherical, or nearly so, with in-rolled edges, white suffused with deep rose to magenta. Petals and sepals are white, flat, and oblong. Leaves are large, elliptical, clasping, heavily ribbed, and hairy.
These perennials bloom between May and August, depending upon location; individual flowers generally last 7-14 days. They are reported to be pollinated by bees; two species of megachilid bees have been observed pollinating them. There are also reports of a small European skipper (a non-native butterfly common throughout much of the showy lady’s slipper’s range) getting trapped in the labellum, preventing pollination by the bees. There has been some speculation that this could lead to a decline of this species’ ability to set seed and reproduce.
Although the glandular hairs on the foliage of showy lady’s slippers can cause a rash, this has not discouraged people from collecting it from the wild; declines in wild populations are thought to be due, at least in part, to over-collecting. Plants dug from the wild usually do not survive, however, and historically, were difficult to cultivate until the late 1990s, when substantial progress was made in axenic culture from sterile seeds. This recent success in cultivating plants in nurseries gives orchid enthusiasts a way of enjoying the plants without harming wild populations. Other threats to the species include loss of wetland habitats, declining water quality, and herbivory by white-tailed deer.
Native to the Northeast and Midwest, the showy lady’s slippers’ most common habitat is wetlands (forested or open) and moist woods, generally in limy sites, at low to moderate elevations. It has probably always been rare, and although it produces a large number of tiny seeds per fruit, reproduction is largely vegetative. Rhizomes can live indefinitely, and plants may live up to 50 years, taking up to 16 years to flower for the first time.
In the United States, showy lady’s slippers are listed as endangered, threatened, historical, exploitatively vulnerable, or special concern in 14 states. They became the state flower of Minnesota in 1902, where there were favored adornments of rural, church alters until it became illegal to pick the flowers or dig up the plants in 1925. In Vermont, where they are on the “List of Rare and Uncommon Native Vascular Plants”, an historical population that had not been seen since 1902 was rediscovered by Green Mountain National Forest staff in 2009, and consisted of more than 1000 plants