Campanulaceae
Lobelia inflata
Indian tobacco · Pukeweed · Lobelia
- Part used
- aerialseed
- Native range
- Eastern North America
- Morphology
- An annual or biennial to about a metre, with toothed leaves and small pale blue-violet flowers, followed by the inflated seed capsules that give the species its name.
What is in it
Evidence
Trials of lobeline for smoking cessation, its most-studied application, have not shown benefit. No supported therapeutic use.
Safety
A powerful emetic with a narrow margin. Nausea, vomiting, sweating, tremor, hypotension, and at higher doses convulsions, respiratory depression and coma. Fatalities are recorded. Lobeline acts at nicotinic receptors, which is the basis of both its historical use and its toxicity.
Interactions: Additive with nicotine and nicotinic agents
Regulatory: Restricted or prohibited as a medicine ingredient in several jurisdictions including Australia.
Historical use
Used by several eastern North American peoples, including as an emetic and in respiratory complaints. Adopted heavily by Samuel Thomson in the early nineteenth century, whose system made it a principal remedy and who was tried for murder after a patient died following treatment.
Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.
What it is taken for, and who says so
Sold in small quantities for respiratory complaints and as a smoking cessation aid, the latter on a mechanism that does not hold up.
Recorded because it is what people believe, not because it is what the plant does. Whether any of it holds up is the Evidence section above, and the two frequently disagree. A sincere account of feeling better is compatible with the plant doing nothing — see the placebo effect.
Worth knowing
Lobelia is the plant that exposed the flaw in Thomsonianism, and the flaw was structural rather than botanical.
Thomson's system held that heat is life and cold is disease, and prescribed lobelia as the opening move in almost every case — administered by anyone who had bought a twenty-dollar family right, with no training and no way to judge a dose. He was acquitted of murder in 1809, and the acquittal did not make the underlying arrangement safe.
Nomenclature verified against GBIF backbone taxonomy.