Isotria medeoloides

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Isotria medeoloides
Isotria medeoloides2.jpg
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Vanilloideae
Tribe: Pogonieae
Genus: Isotria
Species: I. medeoloides
Binomial name
Isotria medeoloides
(Pursh) Raf.

Isotria medeoloides, commonly known as small whorled pogonia or little five leaves, is a terrestrial orchid found in temperate Eastern North America.


The orchid's range is from southern Maine south to Georgia and west to southern Ontario, Michigan, and Tennessee. A population was found in Missouri in 1897,[1] but the plant is no longer believed extant there.[2]

It has always been considered a rare species, often legendarily so. It has been called "the rarest orchid east of the Mississippi."[3]

The plant's habitat includes hardwood and conifer-hardwood forests, where it is found in leaf litter along small "braided" intermittent streams. It native range includes the Appalachian Mountains and Great Lakes region.


Isotria medeoloides is a rhizomatous herb producing a waxy gray-green stem up to about 25 centimeters tall. The gray-green leaves are up to 8.5 centimeters long by 4 wide and are borne in a characteristic whorl.

The flower has green and green-streaked yellowish petals measuring between 1 and 2 centimeters long.[4]


The plant is listed as a threatened species by the U.S. Fish and Wildlife Service, having been downlisted from endangered status in 1994 as more populations were discovered and several were given protection.[2] It is listed as an endangered species by most states or provinces within its range.[5] There are about 104 populations known to exist, but most of these are small, containing fewer than 25 plants.[3]

The main threat to the species' existence is the destruction of its habitat.[3] Other threats include wild pigs, off-road vehicles, predation by deer and slugs, vandalism, and collection.[6]


This orchid is sometimes confused with the common Indian cucumber (Medeola virginiana), which has similar whorled leaves and grows in similar habitat types. The species name medeoloides is a reference to this similarity.[3]

Anecdotal tales of the species only appearing at decades-long intervals do not appear to be supported by field studies. The plant can usually remain dormant for up to three years.[3]


  1. ^ Small whorled pogonia. Missouri Conservationist.
  2. ^ a b USFWS. Isotria medeoloides Five-year Review. October 2008.
  3. ^ a b c d e Isotria medeoloides. Center for Plant Conservation.
  4. ^ I. medeoloides. Flora of North America.
  5. ^ USDA Plants Profile
  6. ^ USFS. I. medeoloides. Celebrating Wildflowers.


  • Gleason, H.A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. New York Botanical Garden, Bronx, New York.
  • Radis, R.P. 1983. Endangered, Threatened, Vulnerable, and Rare Vascular Plant Species of the Delaware Water Gap National Recreation Area. U.S. Department of the Interior, National Park Service, Philadelphia, Pennsylvania.