Pellitory \Pel"li*to*ry\, n. [Sp. pelitre, fr. L. pyrethrum. See Bertram.]

(Bot.)
   (a) A composite plant (Anacyclus Pyrethrum) of the Mediterranean region, having finely divided leaves and whitish flowers. The root is the officinal pellitory, and is used as an irritant and sialogogue. Called also bertram, and pellitory of Spain.
   (b) The feverfew (Chrysanthemum Parthenium); -- so called because it resembles the above.

Source: Webster's Revised Unabridged Dictionary (1913)