The genus Alkanna contains about 50 species that are annual or evergreen perennials and belong to the family Boraginaceae. With only a few cultivated species, plants in this genus are spread from southern Europe and northwest Africa to Iran. Plants are extremely tolerant of dry as well as frosty conditions and grow well in dry, sunny locations, even in poor soil. They are herbaceous with leafy stems and funnel shaped, usually blue but sometimes white and yellow flowers.
Not much to look at, eh? But guess what? The plants are economically important and have medicinal properties as well. Alkanna tinctoria, also known as Dyer's Bugloss or Spanish Bugloss, is cultivated in Central and Southern Europe for its red colored dye. The dye, obtained from the roots is used to add color to perfumes, stain wood and marbles and is even used in thermometers. The dye is also used to make Litmus. The active component, alkanin is soluble in alcohol, ether or benzene. White paper saturated in alcohol solution of alkanine turns red and when this paper is dipped in alkalis, it turns blue. The root is known to have antibacterial, antipruritic (anti-itching) and vulnerary (wound-healing) properties although clinical accuracy of these properties have not been checked as yet.
Alkanna tinctora is a good candidate for an herb garden where it attracts bees in plenty. It grows well in well-drained sandy or loamy soil in sun or partial shade and thrives in alkaline soils. Acidic soil, however, impedes growth. It can be propagated through seeds, basal cuttings or root cuttings.It is indeed good to know that among the list of the well known genera such as Rosa, Dahlia and Darwinia, there is also a genus called Alkanna.