ETYM Arabic hinnâ alcanna (Lawsonia inermis or alba). Related to Alcanna, Alkanet, Orchanet.
A reddish brown dye used especially on hair.
Small shrub Lawsonia inermis of the loosestrife family Lythraceae, found in Iran, India, Egypt, and N Africa. The leaves and young twigs are ground to a powder, mixed to a paste with hot water, and applied to fingernails and hair, giving an orange-red hue. The color may then be changed to black by applying a preparation of indigo.
Henna may also be used to dye both natural and synthetic textiles.

To apply henna to one's hair.