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Great Blue Lobelia, Blue Cardinal Flower - Lobelia siphilitica


Family: Campanulaceae - Bellflower family Genus Common Name: Lobelia Native Status: NativePerennial Herb
Lobelia siphilitica - Great Blue Lobelia, Blue Cardinal Flower. The species epithet is because at one time it was believed the plant was used by native American to treat syphilis. Ingestion of the root can cause vomiting. It should be considered poisonous. References: * Wildflowers of Tennesse by Jack B. Carman * National Audubon Society Field Guide to North American Wildflowers Eastern

Journal Articles Referencing Lobelia

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Lobelia siphilitica

Distribution of Lobelia siphilitica in the United States and Canada:
USDA Plants Distribution Map temporarily unavailable.
Blue=Native; Grey=Introduced

Map from USDA Plants Database:
USDA, NRCS. 2017. The PLANTS Database (http://plants.usda.gov, 25 Jun 2017). National Plant Data Team, Greensboro, NC 27401-4901 USA.

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Site: Walker County, Ga Date: 2009-August-26Photographer: Gerald C Williamson
Great Blue Lobelia has the 'normal' but interesting petal structure for lobelias, with two lips, the upper lip being split with two lobes, and the lower lip having three lobes. The stamens form a tube around the style.
Lobelia siphilitica

Site: Walker County, Ga Date: 2009-October-19Photographer: Gerald C Williamson
Notice the stigma has emerged from the tube formed by the stamen in this mature Lobelia siphilitica specimen.
Lobelia siphilitica

Site: Walker County, GA Date: 2012-August-27Photographer: Gerald C Williamson
Nikon D7000
The older photos on this page were taken after sunset with long exposures, skewing the colors. This photo is closer to true.
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Lobelia siphilitica

Site: Blue Ridge Parkway, Virginia Date: 2014-September-03Photographer: Gerald C Williamson
Nikon D7000
Roadside Great Blue Lobelia on the Blue Ridge Parkway in western Virginia.
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Lobelia siphilitica

Site: Walker County, Ga Date: 2014-September-10Photographer: Gerald C Williamson
Nikon D7000
While most publications report Great Blue Lobelia as 3 to 4 feet tall, clearly this one is taller, as I am 5 feet 9 inches tall. I might be standing in a small depression, but if so it is no more than 4 inches deep. This plant is at least 5 feet tall, I think more likely 6.
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Lobelia siphilitica

Site: Walker County, Ga Date: 2009-October-19Photographer: Gerald C Williamson
While a few blossoms remain along the plant, the Great Blue Lobelia seeds are developing by mid-October in north Georgia.
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Lobelia siphilitica

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All content except USDA Plants Database map Copyright Gerald C. Williamson 2017
Photographs Copyright owned by the named photographer