Редкие виды рода Rhamnus L. (Rhamnaceae) в Восточном Забайкалье

Abstract

The paper presents research data on rare species of the genus Rhamnus in Eastern Transbaikalia. The study shows that R. parvifolia bush is a common species in the region, which grows on open stony slopes and skirts of Dauria. The other two species R. erythroxylon and R. davurica are considered the relicts of nemoral flora and are not widely spread in the region. We found a new hybrid genic species R. × pissjaukovae along with R. erythroxylon and R. davurica, in the elm family of Ulmus pumila in the place Nigaer, near the village of Ust-Urluk, Krasnochikoysky district, Eastern Transbaikalia. The table describes morphological characteristics of similarities and differences between these three species. The three species mentioned (R. davurica, R. × pissjaukovae и R. erythroxylon) are included into a new edition of the Red Data Book of Trans-Baikal Territory. The research carried out shows that cenosis with the species of the genus Rhamnus includes the species from the Red Data Book of Trans-Baikal Territory, miocene-pliocene relicts of xerophilous Mediterranean flora, i.e. Artemisia rutifolia, Melicavirgata,Athraphaxis pungens, Physochlaina physaloides, as well as mesophilous miocene-pliocene relict of Menisprmum dauricum. Therefore, a botanical nature reserve should be organized for their preservation.