Pogonia, Small Whorled

views updated

Pogonia, small whorled

Isotria medeoloides

division: Magnoliophyta

class: Liliopsida

order: Liliales

family: Orchidaceae

status: Threatened, ESA

range: Canada, USA

Description and biology

The small whorled pogonia is considered one of the rarest orchids in eastern North America. It is classified as a perennial (plant that lives, grows, flowers, and produces seeds for three or more consecutive years). It has a waxy, pale green or purplish stem that grows 3.5 to 10 inches (8.9 to 25.4 centimeters) high. The stem is topped by five or six drooping, dusty green leaves arranged in a whorl, or spiral (hence the plant's common name). Each leaf measures 0.8 to 3.3 inches (2 to 8.4 centimeters) in length.

Growing above the leaves are one or two yellowish-green flowers that bloom in May and June and then die very quickly. The sepals (leaflike external whorls lying below the petals of the flowers) are green and narrow, measuring up to 1 inch (25 centimeters) in length. The petals are lance-shaped.

Botanists (people specializing in the study of plants) believe this species of orchid does not depend on insects in order to

pollinate (transferring pollen to the female parts of flowers), but is self-pollinating.

Habitat and current distribution

In Canada, the small whorled pogonia is found in Ontario. In the United States, it is found in the following states: Connecticut, Delaware, Georgia, Illinois, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, and Virginia. The largest populations are in Maine and New Hampshire. Botanists estimate that approximately 1,500 individual small whorled pogonias currently exist.

The plant prefers to inhabit dry, open forests dominated by deciduous (shedding) trees, where it grows in acidic soil.

History and conservation measures

The small whorled pogonia has decreased in number because of many factors. The destruction of its habitat to create land for residential and industrial areas has been the main threat to this species. Because of the plant's beauty and scientific value, it has also been overcollected by private collectors and scientists.

The status of the small whorled pogonia has improved. While it was previously considered endangered, it is now viewed as threatened. Continuing conservation efforts include protecting existing populations and, especially, habitat.


In 1995, the New Hampshire chapter of the Nature Conservancy, a nonprofit environmental organization, purchased 170 acres (68 hectares) at Mount Teneriffe, near the town of Milton, for use as a wildlife preserve. Biologists (people who study living organisms) consider this site to be one of the five most significant sites for the small whorled pogonia in the world. Besides providing a safe habitat for the plant, the new preserve also provides a safe haven for a variety of birds and other rare plants. In addition to being open to the public, the preserve serves as a research area for university scientists and graduate students.