​CATHA, the khat of the Arabs, a shrub widely distributed and much cultivated in Arabia and tropical Africa from, Abyssinia to the Cape. The dried leaves are used for the preparation of a kind of tea and also as tobacco. The plant is a member of the natural order Celastraceae, a family of shrubs and trees found in temperate and tropical climates and represented in Britain by the spindle-tree (Euonymus europaeus).