Alkanet or dyers' bugloss (Alkanna tinctoria) is a plant in the borage family Boraginaceae with a bright blue flower, used to provide a red dye.
A. tinctoria is also known as orchanet, Spanish bugloss or Languedoc bugloss. Its name comes from the Spanish word alcana, from Arabic al-hena, after henna, (Lawsonia inermis).
Alkanet is grown in the south of France and on the shores of the Levant. It has a dark red root of blackish appearance externally but blue-red inside, with a whitish core. The root produces a fine red colouring material which has been used as a cloth dye and to give colour to tinctures, vegetable oils, wines, varnishes, etc. It was often used to improve the appearance of poor grades of port and similar wines, and to give the appearance of age to port wine corks. It is commonly used today as a food colouring E103 (alkannin).
It was listed in the 1918 Dispensatory of the United States of America as a colouring agent.
Alkanet is traditionally used in Indian food under the name "Ratan Jot", and lends its red colour to some versions of the dish Rogan Josh. Ratan Jot is one possible derivation of the famous curry's name.