Skip to page content Skip to site menu

Great Blue Lobelia

A drawing of a plant

Description automatically generated with medium confidence
This image of Great Blue Lobelia comes from William Barton’s Vegetable Materia Medica of the United States. From Similar books available at the John Martin Rare Book Room at Hardin Library.   

Great Blue Lobelia (Lobelia siphilitica)

Lobelia siphilitica, found throughout the US and Canada in wetlands and swamps, is a herbaceous perennial in the Bellflower Family. It grows up to three feet tall, with long racemes of blue flowers, a favorite of hummingbirds. Historically, Native Americans used the plant’s roots and leaves to treat coughs, nosebleeds, headaches, colds, and, as its scientific name would suggest, syphilis (Anderson, 2003; Folquitto et al., 2019). Ingesting Great Blue Lobelia leaves can cause nausea, vomiting, diarrhea, or, in larger amounts, death. Modern use includes extracting an alkaloid, lobeline, used in over-the-counter smoking cessation aids, although there is little evidence of its effectiveness for smoking cessation (Stead & Hughes, 2012). However, lobeline and related piperidine alkaloids are used in several antidepressant and opioid medications (Brown et al., 2016; Vitaku et al., 2014). 

Historical Use

Historical information on the use of Great Blue Lobelia can be found in William Barton’s Vegetable Materia Medica of the United States written in 1818. Barton describes the plant as “rank-smelling, particularly the root.” He indicates the root was used by Native Americans to treat syphilis, but also discredits that, noting the lack of evidence for the efficacy of such treatments. Indeed, he reports, Native Americans used the root in combination with many other plants to treat syphilis. 

Latest Research


Anderson, M. K. (2003). Great Blue Lobelia Plant Guide. 

Brown, D. P., Rogers, D. T., Gunjan, S. K., Gerhardt, G. A., & Littleton, J. M. (2016). Target-directed discovery and production of pharmaceuticals in transgenic mutant plant cells. J Biotechnol, 238, 9-14. 

Folquitto, D. G., Swiech, J. N. D., Pereira, C. B., Bobek, V. B., Halila Possagno, G. C., Farago, P. V., Miguel, M. D., Duarte, J. L., & Miguel, O. G. (2019). Biological activity, phytochemistry and traditional uses of genus Lobelia (Campanulaceae): A systematic review. Fitoterapia, 134, 23-38. 

Stead, L. F., & Hughes, J. R. (2012). Lobeline for smoking cessation. Cochrane Database Syst Rev, 2012(2), Cd000124. 

Vitaku, E., Smith, D. T., & Njardarson, J. T. (2014). Analysis of the structural diversity, substitution patterns, and frequency of nitrogen heterocycles among U.S. FDA approved pharmaceuticals. J Med Chem, 57(24), 10257-10274. 

Other Resources

Natural Medicines record: Lobelia.  (Access to UI only)