Additions to the flora of the Kostroma region based on the materials of 2020

The article presents data on important floristic findings made in 2020 in Kostroma region. Four vascular plant species ( Cardamine occulta Hornem., Malva moschata L., Phedimus aizoon (L.) 't Hart, and Veronica opaca Fr.) are neophytes new to the flora of the study region. In addition, we provide new data on the distribution of twelve plant species rare in the Kostroma Oblast, of which six taxa are alien ( Epilobium tetragonum L., Geranium pusillum L., Poa supina Schrad., Senecio dubitabilis C. Jeffrey et Y.L. Chen, Thladiantha dubia Bunge, and Urtica urens L.) and six are native ( Calamagrostis obtusata Trin., Epilobium parviflorum Schreb., Epipogium aphyllum Sw., Ranunculus subborealis Tzvelev, Veronica teucrium L., and Veronica urticifolia Jacq.). Data presented are important for alien species spread recording and nature conservation in the region.