Adventitious plant species in flora of Sebezhsky national park (Pskov region)
Flora of vascular plants of Sebezhsky national park (NP) consist of 923 species. 200 species belonging to 41 families are adventitious (including archaeophytes). The Asteraceae and Poaceae families are the leaders in the number of adventitious species, as well as in the entire flora of the national park. 101 species belong to weeds and ruderal, 30 species are invasive, of which 18 come from culture, 46 species (non invasive) come from culture, 23 species are imported on the railway and in the city of Sebezh. 11 invasive species appeared on the territory of the NP in the last 30 years and is now being actively implemented in the natural community (Amelanchier spicata (Lam.) C. Koch, Aronia mitschurinii Skvorts. et Maitul., Bidens frondosa L., Echinocystis lobata (Michaux) Torr. et A. Gray, Erigeron annuus (L.) Pers., Festuca arundinacea Schreb., Heracleum sosnowskyi Manden., Impatiens glandulifera Royle, Impatiens parviflora DC., Lupinus polyphyllus Lindl. Solidago canadensis L.). The most rare among adventive species are Anisantha sterilis (L.) Nevsky, Galeopsis pubes-cens Bess., Galium tricornutum Dandy, Papaver argemone L., Stachys annua (L.) L.