A weedy perennial plant (Persicaria maculata) having clusters of small pinkish flowers and usually a dark blotch near the center of the leaf.
An annual plant (Polygonum persicaria) of the buckwheat family, with dense spikes of pinkish or purplish flowers.
Origin of lady-s-thumb
- Possibly from the belief that the blotch was left by the Virgin Mary when she pinched a leaf and rejected it while looking for water pepper, a similar plant that lacks the blotch and is used as a condiment
From American Heritage Dictionary of the English Language, 5th Edition