Epipactis albensis (Orchidaceae) species new to the flora of Lithuania. Data from the northeastern limit of the species distribution area

Epipactis albensis Nováková & Rydlo (Orchidaceae), a species new to the flora of Lithuania, was found in the southwestern part of the country, in the Bukta Forest (the Žuvintas Biosphere Reserve, Marijampolė district) in 2020, and the nearby Dalginė Forest (the Dalginės Botanical Reserve) in 2021. The closest isolated population is located ca. 340 km southwest, and newly recorded populations form an island outside the main distribution area. Species populations occur primarily in the Tilio-Carpinetum betuli plant community showing ecological plasticity. A part of the population occurs in habitats with anthropogenic influence. Epipactis albensis is the only obligate autogamous Epipactis species known in Lithuania until now. Although its flowering season starts at the end of July or the beginning of August, solitary flowering specimens can be found in September or even later. According to the assessment applying the IUCN criteria, species should be treated as endangered (EN) [B2a,b(ii)c(iv) D] in Lithuania.