Myrrh trees (Commiphora sp.) growing in semi-arid desert. The resin of this tree is harvested for aromatherapy and medicinal uses. Known as myrrh or guggul, the resin is burnt as incense, or oil is extracted for use as an antiseptic, stimulant and tonic. Photographed on the island of Socotra, which lies in the Indian Ocean at the mouth of the Gulf of Aden, 340 kilometres (km) from mainland Yemen and 250km from the coast of Somalia. Its isolation has led to the evolution of a unique flora and fauna.