Schistidium halinae (Grimmiaceae, Bryopsida), a new moss species from the Antarctic

Schistidium halinae Ochyra (Grimmiaceae, Bryopsida) is described as a new s pecies based on ten collections from the maritime West Antarctic. It differ s from the congeners in (1) its piliferous upper leaves giving the plants a hoary appearance, (2) sharply spinulose-denticulate, hyaline, broad, flatt ened and membraneous hair-points, 0.2-1.0 mm long on the upper leaves, (3) narrowly recurved and partially bistratose margins in the upper half leaf, (4) presence of a large central strand, (5) short-rectangular and sinuose l aminal cells in the lower middle, and (6) long-rectangular basal juxtacosta l cells with straight incrassate walls and quadrate to short-rectangular ba sal marginal cells forming a band 4-6 cells wide. Additionally, the capsule s are deeply immersed in the ovate perichaetial leaves with a plane or narr owly recurved margin on one side below the apex and terminated with a long, hyaline hair-point (0.6-1.4 mm). The exothecial cells are mostly isodiamet ric to oblong, thin-walled with distinct corner thickenings and the peristo me teeth are erect, lanceolate, perforate to irregularly cracked. The new s pecies is fully described and illustrated and its affinities are discussed. Schistidium halinae is currently known from King George and Livingston Isl ands in the South Shetland Islands and from Vega and James Ross Islands nea r Trinity Peninsula on the NE coast of the Antarctic Peninsula. The distrib ution is mapped.