SPECIMENS EXAMINED. — Antarctica. West Antarctic Peninsula, Danco Coast, Graham Passage region, Pefaur Peninsula, Santos Peak Point, 64°24’29.66”S, 61°31’05.92”W, in wet site in the bryophyte carpet and mat subformation, 30.I.2020, Parnikoza 2/20 (KRAM [B-258874]); Graham Coast, Barison Peninsula, Waugh Mountain, 65°31’08.72”S, 64°04’56.21”W, sparsely on the moist ground in the bryophyte carpet and mat subformation, 25.II.2020, Parnikoza 14/20 (KRAM [B-258886]).
Warnstorfia sarmentosa is a hydrophyte which in the Antarctic is one of the most important constituents of the communities of bryophyte carpet and mat subformation which occupy a wide range of wet and often flushed habitats. The species is primarily widespread and locally common and abundant in the two peri-Antarctic archipelagoes of the South Orkney Islands and South Shetland Islands in the northern maritime Antarctic (Lewis Smith 1972; Ochyra 1998a; Kopalová et al. 2014). In the Antarctic Peninsula region its frequency and abundance is rapidly decreasing. On the west side of the northern part of Antarctic Peninsula it was only once collected on the Davis Coast and also a single record is known from James Ross Island on the east side of Antarctic Peninsula (Ochyra et al. 2008a). Surprisingly, W. sarmentosa has not so far been recorded from the mainland Danco Coast or its offshore islands and only after a fairly wide gap in the range it appears disjunctively on the Graham Coast. For many years it was known only from Lahille Island (Ochyra et al. 2008a) at its southernmost locality, where it was rediscovered in 2020. However, it has recently been recorded from Booth (Wandel) Island and on Rasmussen Point on the mainland Graham Coast (Ellis et al. 2020a).
Warnstorfia sarmentosa is recorded for the first time from the Danco Coast where it was found on Pefaur Peninsula on the mainland Antarctic Peninsula (Fig. 10). This locality nicely bridges the two centres of its occurrence on the west side of the Antarctic Peninsula. The species was also collected on Waugh Mountain on the Barison Peninsula at latitude 64°04’56.208”S and it is the southernmost occurrence of W. sarmentosa on the mainland Antarctic Peninsula (Fig. 11).
Warnstorfia sarmentosa is a bipolar species having an arctic-boreal-alpine panholarctic distribution in the Northern Hemisphere with some intermediate occurrences in the northern and central South American Cordillera (Ochyra et al. 2008a), in the East African mountains (Ochyra 1990b) and in New Guinea (Ochyra et al. 1991). In the south-cooltemperate regions in the Western Hemisphere W. sarmentosa occurs in Patagonia, Tierra del Fuego and in the Falkland Islands (Ochyra & Matteri 2001) and extends to the northern maritime Antarctic, whereas in the Eastern Hemisphere it is known from south-eastern Australia and New Zealand (Karczmarz 1971).