Review Of Drosera Intermedia Herbarium Specimens And New Data On Its Distribution And Ecology In Lithuania

Abstract Drosera intermedia Hayne is one of four species of the genus Drosera in Lithuania. It has the status of an endangered species, however, relatively little is known about its abundance, population size and habitat preference. Seven localities of the species have been indicated in Lithuania till now. Evidence of herbaria is known from four localities. Revision of herbarium specimens revealed the fact that only one sample consisting of six plants was proved to be Drosera intermedia. It was collected in Kamanos raised bog. Distribution of D. intermedia based on recent findings includes two localities in the northern and the eastern parts of Lithuania. Detailed investigations of D. intermedia habitat preference and population size were pursued in the Kamanos State Strict Nature Reserve (Akmenė distr.) in 2013–2014 in five sample plots situated in the Rhynchosporion albae W.Koch 1926 community. The highest density of D. intermedia plants was recorded on bare peat in the mosaic microhabitats of Rhynchospora alba (L.) Vahl and Sphagnum spp. Microhabitats with Sphagnum cuspidatum Ehrh. ex Hoffm. were more favourable than that of Sphagnum magellanicum. There were counted 376 (2013) and 322 (2014) individuals in three sample plots. Next year, 83 plants were appended in two additional plots. Vegetative individuals were more abundant in less favourable areas, while up to 30% of the flowering plants were registered in the depressions of bare peat and Rhynchospora alba mosaic.