Schizymenium pusillum A. J. Shaw 1985

Schizymenium pusillum (Hook. & Wilson) A.J.Shaw

SPECIMEN EXAMINED. — Antarctica. West Antarctic Peninsula, Graham Coast, Rasmussen Point, 65°14’49.70”S, 64°05’6.76”W, in fissures of rocks in the short moss turf and cushion subformation, 9.II.2016, Parnikoza 21a/16 (KRAM [B-260625]).

A new locality of Schizymenium pusillum on Rasmussen Point is apparently the first discovery of this species on the mainland Antarctic Peninsula. Hitherto, it was collected only on the offshore islands of the Antarctic Peninsula, including Andrée Island in Charlotte Bay on the Danco Coast and Galindez Island in the Argentine Islands and Rasmussen Island off the Graham Coast (Clarke & Lightowlers 1983). It is one of the rarest species of moss in the Antarctic and is only known elsewhere in the biome from a single record on Livingston Island in the South Shetland Islands (Sancho et al. 1999) (Fig. 6). Like elsewhere, S. pusillum was collected in a sheltered site in crevices of volcanic rock, growing together with Andreaea regularis, Batramia patens Brid. and Pohlia nutans. In the Antarctic, S. pusillum appears to have optimum occurrence on Galindez Island, the largest island in the Argentine Islands where it grows in profusion at several sites, although it is locally abundant on Andrée Island (Ochyra et al. 2008a).

Schizymenium pusillum is a South American subantarctic species having its main centre of occurrence on South Georgia (Clarke 1973 as Mielichhoferia austrogeorgica Müll.Hal.). In continental South America it is rare at altimontane station in the North and Central Andes of Venezuela, Colombia, Peru and Bolivia (Churchill et al. 2000) and from the Serra dos Órgãos National Park in the state of Rio de Janeiro in southeastern Brazil (Ochyra et al. 2008a), a well-known outpost of many southern cool-adapted moss species (Herzog 1925; Sehnem 1955).