Pennsylvania Field Office
Northeast Region

Small Whorled Pogonia
Life History and Biology

Small whorled pogonia Isotria medeoloides

Information adapted from Felbaum, Mitchell, et al. Endangered and Threatened Species of Pennsylvania. Harrisburg, PA: Wildlife Conservation Resource Fund, 1995.

STATUS: Threatened

DESCRIPTION: The small whorled pogonia is a member of the Orchid Family (Orchidaceae). Its stems are grayish-green with thin waxy coverings. The whorl of the five or six leaves near the top of the stem and beneath the flower gives the plant its common name. Plants bloom in May and June.

RANGE AND POPULATION LEVEL: I. medeoloides is a perennial found only in the Eastern United States. It is very sparsely distributed from southern Ontario, Canada and Maine, south to Georgia and west to Illinois. Within this region, only 12 of the 17 states which have historically recorded plant sites, are known to still have them. This species is noted for long periods of dormancy, such that colonies often fluctuate in apparent size from year to year.

HABITAT: Nearly all small whorled pogonia populations occur in second growth or relatively mature forests. Pennsylvania populations seem to be most abundant on dry east or southeast facing hillsides in mixed oak forests. The soils are generally rocky and somewhat acidic.

REASONS FOR CURRENT STATUS: The small whorled pogonia is considered one of the rarest orchids. Data collected by The Nature Conservancy in 1985 show that approximately 52 populations existed from Ontario to South Carolina. The main threats to this endangered orchid are collecting and habitat alteration.

Fact Sheet
5 Year Review
(pdf 1.93MB)
Recovery Plan
(pdf 12.5MB)
Small-Whorled Pogonia: Endangered Orchid on the Edge (video)
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Species Information
Last updated: October 25, 2012
All images by FWS unless otherwise noted.