Catha edulis aka Qat

Catha edulis belongs to the Celastraceae family. People know it as khat or Arabian tea. Its native range runs from Eritrea to South Africa. It grows at forest edges and in woodland, often on rocky hills. It keeps its leaves year-round and grows without hairs. People harvest wild plants and grow it as a crop. People have grown it since at least the sixth century.

When grown as a crop, khat forms a shrub with several main stems. It reaches about 8–20 feet (2.5–6 metres) tall. Wild trees can reach 82 feet (25 metres). Tree forms grow upright with a small, pointed crown. The plant makes two distinct kinds of branches. Upright shoots have reddish bark, with leaves placed in turn along them. Side branches have leaves in pairs, each facing the other. These leaves are a little smaller than those on upright shoots. Side branches first form after about two years of upright growth. Heavy pruning prompts new shoots, called suckers, at the stem bases.

Growers raise khat in highlands of the tropics and subtropics. Crop sites lie around 4,920–8,200 feet (1,500–2,500 metres) above sea level. Mean daily temperatures there range from 16–22°C. Frost and high humidity limit growth. The crop needs about 800–1,000 millimetres of rain over four to six months. It grows in sandy loam through heavy clay. Soil must be deep and drain well. It needs ample organic matter near the surface. Khat accepts soils from moderately acid through alkaline. It does not tolerate salt.

People chew fresh young leaves and soft shoot tips for their stimulant effects. They can make older or dried leaves into a paste for chewing. This use has deep roots in eastern Africa and southern Arabia. Traditional African and Arabic medicine uses the leaves and roots, too. These uses do not prove health benefits or safety. The supplied source lists no known hazards. Yet it gives no detailed review of toxic effects.

Large trees yield strong wood with a fine grain for furniture and building. The wood ranges from golden yellow to brown. It works well with tools. Its pulp also serves in blotting paper. Growers start most new khat plants from cuttings of upright shoots. Fresh seed sprouts in about 15–20 days. It soon loses its power to sprout. Farmers may grow food crops between young khat plants. After five or six years, the shade becomes too dense for this practice.