Dragon's Blood trees, known locally as Dam al-Akhawain, or blood of the two brothers, are seen on Socotra island March 27, 2008. Prized for its red medicinal sap, the Dragon's Blood is the most striking of 900 plant species on the Socotra islands in the Arabian Sea, 380 km (238 miles) south of mainland Yemen and 80 km west of the Horn of Africa. Socotra islands, which harbour many unique species of birds and plants, may gain UNESCO recognition in July as a world natural heritage site. Picture taken on March 27, 2008. To match feature YEMEN-SOCOTRA REUTERS/Khaled Abdullah/Files (YEMEN) 

Visitors from Gulf Arab countries gather under a Dragon's Blood tree, known locally as Dam al-Akhawain, or blood of the two brothers, in the Socotra island March 27, 2008. Prized for its red medicinal sap, the Dragon's Blood is the most striking of 900 plant species on the Socotra islands in the Arabian Sea, 380 km (238 miles) south of mainland Yemen and 80 km west of the Horn of Africa. Socotra islands, which harbour many unique species of birds and plants, may gain UNESCO recognition in July as a world natural heritage site. To match feature YEMEN-SOCOTRA REUTERS/Khaled Abdullah (YEMEN) 

A Saudi businessman (L) checks the sap of a Dragon's Blood tree, known locally as Dam al-Akhawain, or blood of the two brothers, in the Socotra island March 27, 2008. Prized for its red medicinal sap, the Dragon's Blood is the most striking of 900 plant species on the Socotra islands in the Arabian Sea, 380 km (238 miles) south of mainland Yemen and 80 km west of the Horn of Africa. Socotra islands, which harbour many unique species of birds and plants, may gain UNESCO recognition in July as a world natural heritage site. To match feature YEMEN-SOCOTRA REUTERS/Khaled Abdullah (YEMEN) 

A Dragon's Blood tree, known locally as Dam al-Akhawain, or blood of the two brothers, is seen in the Socotra island March 27, 2008. Prized for its red medicinal sap, the Dragon's Blood is the most striking of 900 plant species on the Socotra islands in the Arabian Sea, 380 km (238 miles) south of mainland Yemen and 80 km west of the Horn of Africa. Socotra islands, which harbour many unique species of birds and plants, may gain UNESCO recognition in July as a world natural heritage site. To match feature YEMEN-SOCOTRA REUTERS/Khaled Abdullah (YEMEN) 

Dragon's Blood trees, known locally as Dam al-Akhawain, or blood of the two brothers, are seen in the Socotra island March 27, 2008. Prized for its red medicinal sap, the Dragon's Blood is the most striking of 900 plant species on the Socotra islands in the Arabian Sea, 380 km (238 miles) south of mainland Yemen and 80 km west of the Horn of Africa. Socotra islands, which harbour many unique species of birds and plants, may gain UNESCO recognition in July as a world natural heritage site. To match feature YEMEN-SOCOTRA REUTERS/Khaled Abdullah (YEMEN) 

Dragon's Blood trees, known locally as Dam al-Akhawain, or blood of the two brothers, are seen on Socotra island March 27, 2008. Prized for its red medicinal sap, the Dragon's Blood is the most striking of 900 plant species on the Socotra islands in the Arabian Sea, 380 km (238 miles) south of mainland Yemen and 80 km west of the Horn of Africa. Socotra islands, which harbour many unique species of birds and plants, may gain UNESCO recognition in July as a world natural heritage site. Picture taken on March 27, 2008. To match feature YEMEN-SOCOTRA REUTERS/Khaled Abdullah/Files (YEMEN) 

Two visitors tour among Dragon's Blood trees, known locally as Dam al-Akhawain, or blood of the two brothers, on Socotra island March 27, 2008. Prized for its red medicinal sap, the Dragon's Blood is the most striking of 900 plant species on the Socotra islands in the Arabian Sea, 380 km (238 miles) south of mainland Yemen and 80 km west of the Horn of Africa. Socotra islands, which harbour many unique species of birds and plants, may gain UNESCO recognition in July as a world natural heritage site. Picture taken on March 27, 2008. To match feature YEMEN-SOCOTRA REUTERS/Khaled Abdullah/Files (YEMEN)