What is "avignon berry"

Avignon berry \A`vignon" ber"ry\ (Bot.) The fruit of the Rhamnus infectorius, eand of other species of the same genus; -- so called from the city of Avignon, in France. It is used by dyers and painters for coloring yellow. Called also French berry.

n. The fruit of rock buckthorn, or Avignon buckthorn, of the species (taxlink Rhamnus saxafilis species), (taxlink Rhamnus infectorius species), and others of the same genus, used by dyers and painters for coloring yellow.