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Great Blue Lobelia

( Lobelia siphilitica )


Great Blue Lobelia
Lobelia siphilitica




Sun, Partial Shade

Loam, Humus Enriched

Normal, Moist, Wet




Habitat Considerations

Boreal Shield, Mixedwood Plains

Woodland, Wet Meadow/Prairie/Field, Riparian, Swamp/Marsh, Lakeshores

Pond Edge/Wetland Garden, Woodland
Design Considerations

30 cm

120 cm

Aug - Sep






Birds, Hummingbirds, Butterflies, Bees

Conservation Status

Interesting Tidbits

POISONOUS PARTS: All parts. TOXIC ONLY IF LARGE EATEN IN QUANTITIES . Symptoms include nausea, vomiting, diarrhea, salivation, exhaustion and weakness, dilation of pupils, convulsions, and coma. Toxic Principle: Alkaloids lobelamine, lobeline, and others, plus a volatile oil. (Poisonous Plants of N.C.) Aboriginal peoples used it for a number of medicinal purposes. According to USDA Database, this beautiful plant is fairly easy to grow.(USDA) Seeds mature in the fall and should be planted on top of the soil, or divided in the spring. Habitat Information: This plant likes wet ground in coniferous and other swamps, as well as moist areas shady to full sun areas, common across Canada. (USDA Natural Resources Conservation Service) Garden Uses: As this plant likes wet woodland conditions so don't let the soil dry out. It looks great with other part shade moisture loving plants, like cardinal flower (Lobelia Cardinalis), flat topped aster (Aster umbellatus), and spotted Joe Pye weed (Eupatorium maculatum). (Lorraine Johnson, 100 Easy To Grow Native Plants). To be water conservation friendly, this plant is a great choice in a wet, and full sun or part shade pond garden, at the outflow of a residential downspout, or for use in bioswales or stormwater ponds, where water is captured and held to create periodic or constant wet conditions. (Evergreen) Insect Relationships: Bumblebees are the main visitors, although others include hummingbirds, butterflies, Halictid bees. (Illinois Wildflowers) Traditional Edible, Medicinal Uses: The plant contains a toxic alkaloid called lobeline, which has same effect as nicotine. Root has been used for dropsy, diarrhea, stomach complaints, syphilis, dysentry. Poultice put on sores to stimulate healing. Leaves are analgesic and febrifuge. Infusion believed to be treatment for colds and fevers. Roots of plants were once thought to be a cure for venereal disease, however this was not found to be true. North American First Nations used the root with other plants as a dusting on ulcers. Some tribes also believed it was a cure for arguing, and if the root was added to their food, they would continue being happy together again. A homeopathic remedy is made from the roots (Plants for a Future)

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