Dracocephalum thymiflorum (Lamiaceae) – a species established in the flora of Poland

Dracocephalum thymiflorum is one of three alien species of the genus Dracocephalum occurring in Poland, previously classified as an ephemerophyte. A survey of the locality in Okuniowiec near Suwałki, northeastern Poland, conducted in May 2026, confirmed the persistence of the D. thymiflorum population for over 13 years. The species has permanently colonized a section of the embankment of the Suwałki – Trakiszki railway line connecting Poland with Lithuania.

Compared with 2013, the number of individuals increased from 42 to approximately 200. Currently, it should be treated as a local epecophyte. Further studies are required to better recognize the distribution and dynamic tendencies of the species in the Polish part of the Lithuanian Lakeland.