Corallorhiza odontorhiza (Willd.) Poir.

Autumn Coral Root

Facts About

Accepted Synonyms: Neottia odontorhiza

Corallorhiza odontorhiza, commonly called Fall Coral Root, is widely distributed across eastern and central Canada and the United States, from Quebec to Texas. Like other members of its genus, it is myco-heterotrophic: it primarily obtains nutrients not from photosynthesis but through mycorrhizal fungi. It stays underground until the fall, when it produces a yellow, greenish, or purplish brown stem, with the base of the stem swollen into a bulb-like structure. It produces up to 26 small, reddish purple, brown, or greenish flowers, with a white labellum often spotted with purple. The flowers can be either chasmogamous or cleistogamous; cleistogamous is the most common form. It grows in a wide variety of forested upland areas.

Corallorhiza odontorhiza is globally considered to be secure, but is rare in several northern and western states. It can be distinguished from C. maculata by its later blooming period and undivided labellum.


Individuals of this orchid may have flowers that are either closed and self-pollinating (cleistogamous) or open (chasmogamous). No pollinators have been identified for these open flowers, although in exclusion experiments seed set was very low for chasmogamous plants, leading researchers to believe these flowers are dependent on pollinators.

Notes on Subspecies and Varieties

Corallorhiza odontorhiza has two varieties: Corallorhiza odontorhiza var. odontorhiza is widely distributed across the eastern U.S.and generally has a closed perianth.
Corallorhiza odontorhiza var. pringlei is limited to some populations in the Mid-Atlantic and Great Lakes states and generally has an open perianth.

Ecosystem Type

Forests, woodlands


Leaf arrangement:
this plant has no leaves
Number of leaves on stem:
Form of the labellum:
the labellum is not pouch-like
Labellum outline:
the labellum is simple
Main color of labellum:
Nectar spur:
Inflorescence type:
the inflorescence is a raceme
Labellum characteristics:
the labellum is simple
Labellum length:
2.7–4.6 mm
Sepal length:
3–4.5 mm
Plant height:
2–46 cm
Show All Characteristics

Native to North America


North American Conservation Status & Distribution

Conservation Status

Select a location to view conservation status:

Conservation and Wetland Status
Global Rank Secure
US Status N/A
Canadian Status May Be At Risk

North America Distribution

Adapted from USDA data