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Spiranthes magnicamporum Sheviak
Great Plains Ladies-tresses
Federal Protection: No US federal protection
State Protection: Endangered
Global Rank: G3G4
State Rank: S1
Element Locations Tracked in Biotics: Yes
SWAP 2015 Species of Greatest Conservation Need (SGCN): Yes
SWAP 2025 Species of Greatest Conservation Need (SGCN): Yes
2025 SGCN Priority Tier: High Conservation Concern
Element Occurrences (EOs) in Georgia: 8
Habitat Summary for element in Georgia: Limestone glades
Perennial herb with an erect stem 3 - 24 inches (7 - 60 cm) tall, with several small bracts sheathing the stem. All leaves are clustered at the base of the stem and are usually withered before the plant flowers; they are long and narrow: 6.3 inches long and 0.6 inch wide (16 cm long and 1.5 cm wide). The flower spike is usually up to 6 inches (15 cm) tall with tightly spiraled rows of white or cream-colored, nearly translucent, flowers, with 3 - 4 flowers per cycle of the spiral. Flowers are 0.3 - 0.5 inch (0.8 - 1.2 cm) long, abruptly nodding from the base, with a hood-like bract, and are fragrant. Two narrow lateral sepals spread out, point up, or cross over the center of the flower; an upper sepal and two narrow petals overlap in the center of the flower to form a short tube; the wavy lip petal curves downward, exposing a fleshy, yellow center. Fruits are capsules less than 0.4 inch (1 cm) long, with many dust-like seeds.
Several ladies-tresses species bloom in the fall in northwest Georgia. Great Plains ladies-tresses is distinguished by the lack of stem leaves, the absence of basal leaves during flowering, the (usually) spreading sepals, and the yellow (not green or white) lip petal.
Seven species of Ladies-tresses are rare in Georgia:
Downy Slender Ladies-tresses (Spiranthes brevilabris) occurs in frequently burned wet, pine savannas and flatwoods, cemeteries, and on roadsides through these habitats in the Coastal Plain. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=18671
Eaton’s Ladies-tresses (Spiranthes eatonii) occurs in frequently burned pine savannas and dry flatwoods, cemeteries, and on roadsides through these habitats in the Coastal Plain. For more information, see: http://beta.floranorthamerica.org/Spiranthes_eatonii
Florida Ladies-tresses (Spiranthes floridana) occurs in wet savannas, mowed grassy openings in the Okefenokee area, and on roadsides through these habitats in the Coastal Plain. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=17359
Long-lipped Ladies-tresses (Spiranthes longilabris) occurs in low hammocks with saw palmetto, seasonally wet depressions in pine flatwoods and savannas, fields, and wet roadside ditches in the Coastal Plain. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=19007
Great Plains Ladies-tresses (Spiranthes magnicamporum) occurs in northwest Georgia in grassy areas on limestone cedar glades and in prairie openings in the Coosa River valley. For more information, see: https://www.georgiabiodiversity.org/portal/profile?group=plants&es_id=15517
Northern Oval Ladies-tresses (Spiranthes ovalis var. erostellata) occurs in seepy margins of small streams and floodplain forests throughout Georgia except the southeast corner. For more information, see: http://beta.floranorthamerica.org/Spiranthes_ovalis_var._erostellata
Pale Green Ladies-tresses (Spiranthes sylvatica, synonym S. praecox) occurs in Live Oak hammocks and other open woodlands in the Coastal Plain. For more information, see: http://beta.floranorthamerica.org/Spiranthes_praecox
Grassy areas on limestone cedar glades and prairie openings in the Coosa River valley.
The leaves of Great Plains ladies-tresses emerge in the spring from a stout root, persist through the summer, and begin to wither and disappear several weeks before flowering. Ladies-tresses flowers are pollinated by bumblebees and halictid bees. Self-pollination is discouraged by two sequences of events.
First, when a flower opens, a tiny structure at the center of the flower (the column) is pressed against the flower’s lip, covering the stigma and leaving only a narrow space into which a bee can insert its tongue in search of nectar. While the stigma is covered, the flower can’t be pollinated. As the bee sips nectar, two pollen packets stick to its proboscis. Once the bee exits the flower, carrying with it that flower’s pollen packets, the column lifts up, exposing the stigma. The next bee that comes along to sip nectar – possibly carrying pollen packets from another plant – may brush against the exposed stigma and deposit the pollen.
Second, in order to discourage the movement of pollen between flowers on the same plant, the flowers in a spike open from the bottom to the top of the spike. Bees always work their way from the bottom to the top of a flower spike as they gather nectar. If they pick up pollen from flowers at the bottom of the spike, flowers on the same spike nearer the top will not yet be open and receiving pollen. Instead, the bee flies to an open flower on another plant, gathers nectar, and deposits its pollen load, thus cross-pollinating the flower.
If pollinated, the flowers produce small capsules containing many dust-like seeds that are dispersed by the wind. As with all species of orchid, the seeds of Great Plains ladies-tresses lack endosperm and require the presence of certain species of fungi to germinate and support seedlings.
Surveys must be conducted during flowering (mid-October) since the leaves are not distinctive and are very hard to see.
Georgia, west to New Mexico and north to Pennsylvania and Manitoba.
Conversion of habitat to pine plantations and developments. Fire suppression and encroachment by woody species.
| Threat 1 | Threat 2 | Threat 3 | |
|---|---|---|---|
| General Threat | Agriculture & aquaculture | Energy production & mining | Transportation & service corridors |
| Specific Threat | None | None | None |
Spiranthes magnicamporum is ranked S1 by the Georgia Department of Natural Resources, indicating that the species is critically imperiled in Georgia. It is listed as Endangered by the State of Georgia. Eight populations have been documented in Georgia, 3 on conservation lands and two on private land covered by a conservation easement.
Although Spiranthes magnicamporum is widespread and relatively common in parts of its range, Georgia’s plants are the southeasternmost populations of this species. Plants occurring at the periphery of a species’ range are thought to be of special conservation importance. Peripheral populations are usually smaller and less genetically diverse within the population, but genetically divergent from centrally located populations. These genetic differences may confer special survival traits that plants in other portions of the species’ range lack, such as the ability to survive changes in the climate or the arrival of a new pathogen. Peripheral populations may be in the process of evolving into a new species. They are especially deserving of conservation action.
Conduct prescribed fires to control woody species encroachment. Prevent off-road vehicle access, trampling, and mechanical clearing.
Anderson, A.B. 1991. Symbiotic and asymbiotic germination and growth of Spiranthes magnicamporum (Orchidaceae). Lindleyana 6(4): 183-186.
Brown, P.M. and S.N. Folsom. 2004. Wild orchids of the southeastern United States. University Press of Florida, Gainesville.
Catling, P.M. 1983. Pollination of northeastern North American Spiranthes (Orchidaceae). Canadian Journal of Botany 61(4): 1080–1093. https://www.nrcresearchpress.com/doi/abs/10.1139/b83-116
Chafin, L.G. 2007. Field guide to the rare plants of Georgia. State Botanical Garden of Georgia and University of Georgia Press, Athens.
GADNR. 2020. Element occurrence records for Spiranthes magnicamporum. Georgia Department of Natural Resources, Wildlife Resources Division, Social Circle, Georgia.
Luer, C.A. 1975. The native orchids of the United States and Canada, excluding Florida. New York Botanical Garden, New York.
NatureServe. 2020. Spiranthes magnicamporum species account. NatureServe Explorer. NatureServe, Arlington, Virginia. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.128169/Spiranthes_magnicamporum
Nourse, H. and C. Nourse. 2007. Favorite wildflower walks in Georgia. University of Georgia Press, Athens.
Patrick, T.S., J.R. Allison, and G.A. Krakow. 1995. Protected plants of Georgia. Georgia Department of Natural Resources, Natural Heritage Program, Social Circle.
Proctor, M. and P. Yeo. 1972. Pollination of flowers. Taplinger Publishing Company, New York.
Sheviak, C.J. and P.M. Brown. 2003. Spiranthes magnicamporum species account. Flora of North America, Vol. 26. Oxford University Press, New York. http://beta.floranorthamerica.org/Spiranthes_magnicamporum
Weakley, A.S. 2015. Flora of the southern and mid-Atlantic States. University of North Carolina Herbarium, University of North Carolina, Chapel Hill. http://www.herbarium.unc.edu/flora.htm
Linda G. Chafin
L. Chafin, Aug. 2008: original account
K. Owers, Feb. 2010: added pictures
L. Chafin, May 2020: updated original account
