The floral (phytogeographic) elements are a group of species, which originate from the same geographical region and have similar direction of distribution and changes in the distribution.

Strandja florogeographic complex has a character that is unique in Europe. Situated on a biogeographical crossroads, the mountain hosts not only species from the relic euxeinos flora, but also species from the Mediterranean, Central-European, Balkan, Eurasian, Pontic-Central Asian and Atlantic group of floral elements.

In ecological-biological aspect, the flora in Strandja features a great number of phanerophytes (trees and shrubs) – 7%, which is typical of the mountains, and at the same time a large number of terrophytes (annuals that spend the unfavorable season in the form of germs: seeds, fruits, spores, etc.) – 26%, which in turn is typical of the dry and shallow soils, Mediterranean climate and degradation of the vegetative cover due to anthropogenic activity.