Preliminary information on the composition of alien plant species found along railways in some cities of the Republic of Dagestan is presented. 35 species of 15 families have been identified. The largest number of species (30 or about 85 %) were found within the city of Makhachkala. For the first time, five new species were identified for the alien flora of Dagestan: Cenchrus longispinus (Hack.) Fernald, Caragana halodendron (Pall.) Dum. Cours., Euphorbia maculata L., Lycium chinense Mill. and Panicum capillare Mill. Widespread species are Ailanthus altissima (Mill.) Swingle, Amaranthus albus L., A. retroflexus L., Ambrosia artemisiifolia L., Erigeron canadensis L., Euphorbia davidii Subils, Gleditsia triacanthos L. and Xanthium orientale L. Most alien species (25 or more than 70 %) are of American origin. The main part of the species (23) was brought into the study area through accidental introduction.

R.A. Murtazaliev