Henna

n.
  1. (Bot.) A thorny tree or shrub of the genus Lawsonia (Lawsonia alba). The fragrant white blossoms are used by the Buddhists in religious ceremonies. The powdered leaves furnish a red coloring matter used in the East to stain the nails and fingers, the manes of horses, etc.
  2. (Com.) The leaves of the henna plant, or a preparation or dyestuff made from them.