Survey on the Distribution, Diversity and Phyochemistry of Genus Thymus in Bulgaria

The species of genus Thymus are important medicinal and aromatic plants. They provoke substantial interest worldwide from phytochemical point of view, due to their diverse biological activities with potential for application in pharmaceutical, cosmetic and food industries. The present study reports results of a survey on the distribution and diversity of the species in Bulgaria. Both field investigations and literature data were used in the study. The 20 species distributed naturally in Bulgaria differ in their natural range. The rarest species are Thymus perinicus (Bulgarian endemic) and T. bracteosus, each distributed in only one floristic region. T. leucotrichus and T. stojanovii occur in two floristic regions each, T. longedentatus – in four and the other species are distributed in five or more floristic regions. There are four Balkan endemics. Most widely distributed are T. pannonicus, T. pulegioides and T. sibthorpii, with natural localities in all 20 floristic regions in Bulgaria. Three species are of conservation importance. The richest in species floristic region was Rhodopes with 16 species followed by Pirin – 15, Stara plania – 13, and the least number of species was recorded in the Danubian plain (5). The information is being currently updated with new data and most probably, the species number will increase in most floristic regions. Still, there are many taxonomic uncertainties requiring further investigations that could result either in change of species number, or in change of status of some taxa. Field studies have shown that the species of genus Thymus occur in many different habitat types, ranging from sea shores, through forest and grassland habitats to the alpine zone and rock fissures and screes.