The Bulgarian side of the Strandja mountain is home to 1666 species and 54 sub-species of higher fern, equisetum and seed plants registered in scientific publications and accounting for 47,6% of their species composition in Bulgaria. The fern is represented by 22 species, and the equisetum – by 5 species.

The floristic diversity is even greater at the “family”(121) and “genus” (618) level, whose taxons are represented by more than 70% of the known in Bulgaria species. The Asteraceae has the largest representation – 191 species from 62 genera, followed by Poaceae – 154 species from 72 genera, and Fabaceae – 146 species from 28 genera.

Approximately one hundred species of moss have been found in Strandja Nature Park. The Metzgeria simplex species has been included in the Red Data Book of the European moss and another 14 species have found their place in the List of Rare and Threatened Species in Bulgaria with Strandja being the only habitat for 10 of them and one of the two habitats for the remaining 4 species. The rare species in the park are mainly characterized with transient Atlanto-Mediterranean distribution, which distinguishes them from the prevalent in the Bulgarian moss flora circumpolar species.