Scrophulariaceae
Verbascum thapsus
Mullein · Great mullein · Aaron’s rod
- Part used
- leafflower
- Native range
- Europe, north Africa and Asia; naturalised widely and weedy in North America and Australia
- Morphology
- A biennial forming a rosette of large soft felted grey-green leaves in the first year, then a single unbranched spike to two metres densely packed with yellow flowers.
What is in it
Evidence
Almost no controlled evidence. The demulcent action is a physical mechanism and is not in doubt; the specific respiratory claims are untested.
Safety
Well tolerated. The leaf hairs are irritant and preparations must be strained, or they cause throat itching — this is a real practical point recorded in every traditional source. Seeds contain rotenone and saponins and are toxic; they were historically used to stupefy fish.
Regulatory: Permitted as a listed ingredient.
How the traditions classify it
Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.
Historical use
Used across Europe and, after introduction, in North America for cough and chest complaints. The dried stalks were dipped in tallow and burned as torches, which is where several of its common names come from.
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.
Worth knowing
Mullein carries the two-part instruction that shows a tradition paying attention: use the leaf, strain it thoroughly, and never the seed.
The straining is not fussiness. The leaf is covered in branched hairs that break off and lodge in the throat, and an unstrained infusion is genuinely unpleasant. Every traditional source that describes the preparation says so.
The seed prohibition is sharper. Mullein seed contains rotenone and saponins and was used deliberately to stun fish for catching — a practice widespread enough to have been legislated against in parts of Europe. A plant whose leaf is a gentle demulcent and whose seed is a fish poison is a useful reminder that "part used" is not a bureaucratic field.
Nomenclature verified against GBIF backbone taxonomy.