New data on geographical distribution of Diphasiastrum tristachyum (Lycopodiaceae) in Ukraine

Diphasiastrum tristachyum (Lycopodiaceae) is a rare species of the Ukrainian flora, listed in the Red Data Book of Ukraine. In our country it occurs mainly in Central (Zhytomyr) Polissya. Two localities only have been recorded in Volhynian Polissya. In the literature sources, there is no information about distribution of D. tristachyum in Kyiv Polissya. However, back in 1899, the species was collected near the town of Boyarka (KWU0001665). Although correctly identified, this specimen has not been previously included in distribution data. We report a new locality of D. tristachyum from pine forest in Lub'yanka Forestry in Bucha District, Kyiv Region. In the Podolian Upland, an isolated local population of D. tristachyum was found in a karst sinkhole near Hutysko village, Ternopil Region. A list of all known localities of D. tristachyum in Ukraine and data on the current state of its populations in the newly reported localities are provided. It is proposed to establish a botanical reserve in Lub'yanka Forestry.