Species characteristic for natural communities, like forests and meadows: Leucanthemum vulgare and Lychnis flos-cuculi, were also present in the analyzed material. Three BMS-907351 manufacturer species of crop plants: linen Linum usitatissimum, poppy Papaver somniferum and oat Avena sativa, commonly used for food products like pastry or muesli, were
found. But among collected buy PR-171 material were also present species with range covering polar regions of Northern Hemisphere like for example: Leontodon autumnalis, Carex disticha or Poa annua. Some of them are highly invasive e.g., P. annua or Cirsium arvense (www.cbd.int/invasive/database.shtml) and already establish in sub-Antarctic. A lot of identified species are native to cold region of Eastern Hemisphere and alien to Western Hemisphere (Table 2). The most interesting finding was the presence of caryopses and remains of spikelet of
P. annua in the analysed material. There were several reports of alien plants occurring close to Antarctic stations (e.g., Smith 1996; Hughes et al. 2010a; Hughes and Convey 2010; Chwedorzewska 2009; Hughes and Convey 2010), but only P. annua has survived specific maritime Antarctic conditions for many years and established a stable breeding population (Olech and Chwedorzewska 2011). Poa annua is one of the most widely distributed plants in the world, native to Eurasia (Tutin find more 1952). It is a synanthropic and pioneer species (Huff 2003), adapted to a broad range of climate conditions (e.g., Frenot et al. 2001) and
able to colonize such harsh environments as the maritime Antarctic. Initially P. annua was recorded in the Polish Antarctic Station H. Arctowski King George Island (62°09′S and 58°28′W) in 1985. Followed by a gradual increase of the P. annua Cediranib (AZD2171) population size, first the colonization of synantrophic places (Olech 1996, 1998), then of the forefield of retreat glacier areas (Olech and Chwedorzewska 2011) by this grass took place. Finding caryopses in the analysed material seems to support the genetic analysis of P. annua population from “Arctowski”. This investigation points out that the Antarctic population was probably founded by multiple introduction from different sources (Chwedorzewska 2008). This evidence supports the hypothesis of constant flow of fresh genetic material of this species to the vicinity of the station, which is reflected by an astonishingly high genetic variability in the introduced population (Chwedorzewska 2008; Chwedorzewska and Bednarek 2012). Poa annua’s independent establishment were also documented at General Bernardo O’Higgins (63°19′S; 57°54′W), Gabriel Gonzalez Videal (64°49′S; 62°51′W) and Almirante Brown Stations (64°52′S; 62°54′W). Thus located along the Antarctic Peninsula and associated archipelagoes (Chown et al. 2012a, Molina-Montenegro et al.