Life history

Species overview

Autumn Coral-root (Corallorhiza odontorhiza), a State Special Concern plant, is found in deciduous forests. Blooming occurs early August through early September; fruiting occurs throughout September. The optimal identification period for this species is early August through late September.

Synonyms: Corallorhiza micrantha, Cymbidium odontorhizon

Identification

• Distinguishing characteristics: Distguished from C. maculata and C. trifida by the entire, toothless lip; and from C. striata by the lower lip white with small purple spots and lines confined to the outer margin.
• Flower characteristics: Flowers 5 to 15, drooping, appearing late in growing season (August to September) on a 3 to 6 cm tall stalk; petals 3 to 4.5 mm long, reddish-purple above and with a cream to white lower lip with purple around the edges and small purple spots; lower lip not lobed or toothed, but may have a slightly ragged or wavy lower margin.
• Fruit characteristics: Capsule egg-shaped, pendulous
• Leaf characteristics:

Phenology

• Blooming phenology: early August through early September
• Fruiting phenology: throughout September
• Optimum time to identify: early August through late September

Other

• Growth form: Forb-erect
• Vegetative reproduction:
• Life cycle: Perennial
• Comments: Associated Species: Acer saccharum, A. rubrum, Quercus alba, Q. borealis, Tilia americana, Carya ovata, Betula papyrifera. Mycotrophic (obtains nutrients by parasitizing fungi).

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

Autumn Coral-root (Corallorhiza odontorhiza) is on the "watch list." Watch list species have experienced, or are believed to have experienced, a statewide or range wide decline, but they are not currently tracked in the Natural Heritage Inventory (NHI) database. The watch list includes newly discovered species for which origin and rarity need to be determined, certain animals designated as Species of Greatest Conservation Need (SGCN) in the Wisconsin Wildlife Action Plan, and species that were tracked in the past but proved more abundant, widespread or less vulnerable than previously thought. Although watch list species are not actively tracked by NHI, occurrences documented during surveys are often stored by NHI, as these species could be tracked in the future if there is further evidence of their decline.

Habitats and landscapes

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

General habitat information

• Habitat description: Found in deciduous forests.
• Soils: Wet-mesic to dry or occassionally sandy soils

Natural communities

This table lists the natural communities that are associated with Autumn Coral-root. Scores for natural community associations are: "significant" association (score=3), "moderate association" (score=2) or the species can be present but is only weakly associated with the community (score=1).

Ecological landscapes

This table lists the ecological landscape association scores for Autumn Coral-root. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Species guidance

The Endangered Resources Program has developed avoidance measures and management guidelines for plants on the Natural Heritage Working List. These are a work in progress, and we welcome your suggestions and feedback. Sources used in developing this information can be found here.

Avoidance measures

These are specific actions designed to avoid "take" (mortality) of this species.

• Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.
• Avoid broadcast spraying of herbicides; use care with spot spraying.
• Avoid site preparation that heavily disturbs herbaceous ground layer and soil; these include bulldozing and furrowing, as well as grubbing and stump removal.

Management guidance

Management guidelines are additional considerations that may help maintain or enhance habitat for this species

• This species has a symbiotic relationship with fungi found in the soil. Therefore, avoid soil disturbance, including the use of fertilizers or fungicides.
• Maintain thick duff layer if possible; minimize spread of invasive species including earthworms.

Other resources

Links to additional Autumn Coral-root information

• NatureServe Explorer information [exit DNR]

Other links related to vascular plants (all exit the DNR website)

• Wisconsin Vascular Plants
• Freckmann Herbarium
• Atlas of Wisconsin Prairie and Savanna Flora - Wisconsin State Herbarium
• USDA - NRCS Plants Database
• USGS Midwestern Wetland Flora - field office guide to plant species
• eFloras
• Cofrin Center for Biodiversity Herbarium
• Intermountain Herbarium Grasses of North America
• Orchids of Wisconsin

Photos

Click to view a larger version. Please considering donating a photo to the Endangered Resources Program for educational uses. Photo use