Henna or arjeña 1 (from ar. Hisp. Alḥínna, and this one from Arabic الحناء al-ḥinnā´) or henna or jena is a natural reddish color that is used for hair and which is also used in a coloring technique of the skin called mehandi. It is made with the dried leaf and the petiole of Lawsonia alba Lam. (Lawsonia inermis L.). This dye is commonly used in India, Pakistan, Iran, Yemen, the Middle East and North Africa. The mehandi patterns are quite complex and in some cultures they are used as a bridal ornament. In the West it has been used, although not widely, since the 70s.
To prepare the henna paste, the leaves are crushed to a brownish green powder and mixed with essential oils and lemon juice that release the dye from the leaves and sugar to give consistency. When applied to the skin, the dye turns pale orange and over the course of the hours it darkens until it reaches a reddish brown. In some countries, especially in India, henna paste is sold in cones ready for use. Henna penetrates only the dead cells of the cutaneous stratum corneum, the duration of the dye varies depending on the thickness of the skin, but it is only days.