Here's however what Pliny writes of teasel (25:108):
"Labrum Venereum is the name given to a plant that grows in running streams. It produces a small worm, which is crushed by being rubbed upon the teeth, or else enclosed in wax and inserted in the hollow of the tooth. Care must be taken, however, that the plant, when pulled up, does not touch the ground."
"Labrum Venereum is the name given to a plant that grows in running streams. It produces a small worm, which is crushed by being rubbed upon the teeth, or else enclosed in wax and inserted in the hollow of the tooth. Care must be taken, however, that the plant, when pulled up, does not touch the ground."

