Phenology of Gymnospermium odessanum (DC.) Takht. in the M. M. Gryshko National Botanical Garden of NAS of Ukraine

Abstract

The aim is to find out the peculiarities of the phenology of the rare endemic species Gymnospermium odessanum (DC.) Takht. in the conditions of introduction on the botanical-geographical plot “Steppes of Ukraine” of the M. M. Gryshko National Botanical Garden, National Academy of Sciences of Ukraine in 2021. Methods — field stationary and cameral. It is established that the vegetation period of G. odessanum in 2021 lasted from March 24 to May 22 and amounted to 60 days. 10 phenological phases are singled out and characterized: 1) the beginning of vegetation and budding, 2) mass budding and beginning of flowering, 3) mass flowering and completion of budding, 4) flowering peak, 5) mass flowering and the beginning of fruit formation, 6) completion of flowering and mass fruit formation, 7) fruit growth, 8) fruit opening, 9) ripening of seeds in open capsules, 10) dissemination and completion of the vegetation. It was found that during the mass formation of fruits, a significant number of fruits stopped their growth and development and did not form seeds in the future. This could be due to the night frosts on the eve or the difference in the conditions of the region of introduction from the natural habitats of the species. Budding and flowering (in total) account for a smaller part (30%) of the vegetation period. Most (70%) of the vegetation period is associated with fruits and seeds. A significant proportion of the vegetation period is the phenophase of ripening of seeds in open capsules (27%).