# Teasel (Dipsacus fullonum)

*Fuller’s teasel; Venus’s basin*

**Known today as.** *Dipsacus fullonum*. A tall, prickly biennial whose paired leaves clasp the stem to form a natural cup that fills with rainwater.

Kind: Plant

## What was it used for?

The dried, hooked flower heads used for centuries to raise the nap on woolen cloth, whence the cultivated form’s name, fuller’s teasel; medieval herbalists also prescribed the plant for fistulas, hemorrhoids, and boils.

## What does modern science say?

No controlled evidence supports its old medicinal uses; its use in finishing cloth was genuine and lasted into the industrial age before metal card teeth replaced it.

## Pharmacognosy and toxicology

- **iridoid glycosides**: sylvestroside, loganin
- **caffeic acid derivatives**: 
- **saponins**: 

**Mechanism.** A plant of the cloth trade whose root was a mild diuretic and bitter; the modern claim of a teasel-root cure for Lyme disease has no trial and no mechanism, and the iridoids showed weak activity against *Borrelia* in one laboratory study.

**Dose.** Safe.

**Standing.** No monograph; the Lyme claim is folk internet medicine.

## What lore surrounds it?

The water gathered in its leaf cups was called Venus’s lip by the Romans and Venus’s basin by Renaissance writers, and was believed to have cosmetic and healing power, above all against warts. The medieval prescriptions reasoned from the plant’s prickly look that it suited piercing, stubborn ailments.

## What did the older authorities say?

**Pliny.** “The dipsacos has leaves like those of the lettuce, with prickly tubercles on the middle of the back. The stem of it, two cubits in length, is bristling all over with prickles of a similar nature. The joints of the stem are closely covered with two leaves, which form a concave axil in which a saltish dew-like liquid collects.” Pliny gives the small prickly heads, the watery habitat, and two uses: the root boiled in wine “to the consistency of wax” as a salve for fistula, and for warts, “the juice collected in the axils, as above mentioned, is also used by some.”

## Sources

- The Metropolitan Museum of Art, “Wild Teasel.”
- Pliny the Elder, *Natural History* 27.47, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library.
- Liebold, T., et al. (2011). “Growth inhibiting activity of lipophilic extracts from *Dipsacus sylvestris* roots against *Borrelia burgdorferi* in vitro.” *Pharmazie* 66.

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*Teasel.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/teasel

Historical description, not medical advice.