The following is a brief phytogeographical sketch of the forests of the western portion of the Caucasus range, which I visited in 1912 as a member of the excursion to the Caucasus and Armenia arranged and conducted by Prof. M. Rikli of Ztirich, whose " Naturwissenschaftliche Studienreisen " are so well known to and appreciated by botanists, as well as by workers in other fields, that I need not give particulars concerning them here, beyond mentioning that those interested will find details-botanical, zoological, geological, ethnographical, etc.-in the book edited by Prof. Rikli giving an account of the 1912 excursion2.