|Henna (Lawsonia inermis, also known as hina, the henna tree, the mignonette tree, and the Egyptian privet) is a flowering plant and the sole species of the Lawsonia genus.
The henna plant is native to northern Africa, western and southern Asia, and northern Australasia, in semi-arid zones and tropical areas. It produces the most dye when grown in temperatures between 35 and 45 °C (95 and 113 °F). During the onset of precipitation intervals, the plant grows rapidly, putting out new shoots. Growth subsequently slows. The leaves gradually yellow and fall during prolonged dry or cool intervals. It does not thrive where minimum temperatures are below 11 °C (52 °F). Temperatures below 5 °C (41 °F) will kill the henna plant. (Source: Wikipedia)