KNP Rare Plants Database

KY Office of Kentucky Nature Preserves

Great Plains Ladies'-tresses
Spiranthes magnicamporum
Family: Orchidaceae

Protection Status:
State Status:  T
USFWS Status: 

Global Rank: G4
State Rank: S2


Photo by KSNPC Staff
Calcareous soil in prairies, and glades.

Species Description:
Perennial herb.

Flowering Period: Early September to late October.

Additional Information at NatureServe

Diagnostic Characteristics:
Ladies-tresses orchids have flowers spirally arranged in a spike along the peduncle. S. magnicamporum is distinguished by having linear narrowly pointed leaves absent at the time of flowering, which is in the fall, usually around October. Lateral sepals of the flowers spread and arch above the upper petal tips and the lip yellowish. The flowers produce a sweet vanilla like odor.

Woody plant invasion may need to be controlled using periodic prescribed fire, mowing or other means to maintain the open character of the habitat for this species. Hand removal of trees in the vicinity of the species is necessary. Soil disturbance resulting from activities such as ATV trails, timber removal or any activity that results in increased erosion and weed invasion will be detrimental. Exotic pest plants are a threat to this species and should be removed.

Global Range:
Eastern Great Plains, Great Lakes and Midwest regions, with disjunct populations in Utah, Colorado, New Mexico and Alabama-Mississippi (Luer 1975). Also into Ontario and Manitoba (Kartesz unpublished data 1995).

Known Kentucky Occurrences:
Species occurrence map

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Data Last Updated: November 2018
Office of Kentucky Nature Preserves
300 Sower Blvd
Frankfort,KY 40601
Phone: (502) 573-2886
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