henna

description
Henna is a tall shrub or small tree of the Lyrthraceae family, standing 1.8 to 7.6 m (5 ft 10 in to 24 ft 10 in) tall. It is glabrous and multi-branched, with spine-tipped branchlets. The leaves grow opposite each other on the stem and are glabrous, sub-sessile, elliptical, and lanceolate (long and wider in the middle; average dimensions are 1.5–5.0 cm x 0.5–2 cm or 0.6–2 in x 0.2–0.8 in), acuminate (tapering to a long point), and have depressed veins on the dorsal surface. Henna flowers have four sepals and a 2 mm (0.079 in) calyx tube, with 3 mm (0.12 in) spread lobes. Its petals are obvate, with white or red stamens found in pairs on the rim of the calyx tube. The ovary is four-celled, 5 mm (0.20 in) long, and erect. Henna fruits are small, brownish capsules, 4–8 mm (0.16–0.31 in) in diameter, with 32–49 seeds per fruit, and open irregularly into four splits.

common names & nomenclature
The English name "henna" comes from the Arabic word pronounced as hinna.

Also known as:
hina, henna tree, mignonette tree, egyptian privet, henne, al-khanna, al-henna, jamaica mignonette, mehndi, mendee, smooth lawsonia

The henna plant is native to northern Africa, western and southern Asia, and northern Australasia.

climate
Henna grows in sunny semi-arid zones and tropical areas. It does not thrive where minimum temperatures are below 11 °C. Temperatures below 5 °C will kill the henna plant.

soil
Henna grows well in a sandy, well-draining soil similar to a cactus mix.

growing
Sow henna seeds in March-April, cover lightly with compost and be patient: germination can be slow, sometimes several months. The process may be speeded up by sealing the pot inside a plastic bag and putting it in a warm place, such as a greenhouse. Once germinated, pot seedlings up on into individual pots and keep in a sunny location. Water well during the growing season and repot annually every spring. Flowering will not take place until the plants are at least 5 or 6 years old.

harvesting
Surplus leaves can be clipped from the plant as soon as it is large enough, and these can be dried and ground into powder.

preserving
Store powdered henna in an airtight container in a cool, dry place.