The island of Socotra lies off the north-east corner of Africa, in lat. 12° 19′ to 12° 42′, and long. 53° 20′ to 54° 30′. Its extreme length from east to west is about 72 miles, and its breadth about 22 miles. From Cape Guardafui 140 miles, it is a little more distant from the Arabian coast (about 500 miles from Aden), and still further away from the Indian Peninsula. It is the most easterly elevation of land on a coral bank lying to the north-east of Africa, upon which, between it and Cape Guardafui, other islands (Abd-al-Kuri, Kal Farun, Samneh and Darzi—known commonly as The Brothers—and Saboynea) of smaller size occur. On no part of this bank is the depth of water over 200 fathoms, but between it and the African coast is a channel reaching 500 fathoms. Around Socotra is a narrow coral reef.

A considerable tropical order of, with but few exceptions, climbing plants, occurring in both the old and new worlds. A few species are found in the cooler regions of North America, Eastern Asia, South Africa, and Australia.