SCHISTIDIUM SORDIDUM NEW TO TURKEY AND SOUTHWEST ASIA

Schistidium sordidum I. Hagen (Grimmiaceae) is recorded for the first time in Southwest Asia (Turkey). The specimen was collected in the south (Ağrı Mountain) of Iğdır province, East Anatolia Region of Turkey. The nearest locality to Turkey for this species is Russia. A site description, illustrations, ecology, distribution and diagnostic characters of the species are presented.


INTRODUCTION
Ağrı Mountain, an ancient volcanic mountain, is located 35 km from the border of Turkey and Armenia.Phytogeographically it belongs to the Irano-Turanian floristic region.Ağrı (5137 m), which is the highest mountain in Turkey, the third highest mountain in Europe and Southwest Asia after Elburz (Iran) and Ebruz Mountain (Caucasia) (Özhatay et al., 2005).The mountain is exposed to high light conditions and is windswept, with a gently sloping terrain comprising grass and volcanic calcareous rocks, and poor streams with scattered coniferous and deciduous trees, such as Juniperus communis L., Populus tremula L., Betula sp., Crataegus pseudoheterophylla Pojark, and Salix sp.occasionally from 1700 to 2100 m (Baytop and Denizci, 1963).It is situated in the south of Iğdır province.The climate of the study area is characterized by hot dry summers and cold snowy winters.The mean annual temperature is 11.6°C, average humidity is 63%, and the mean annual rainfall is about 257.6 mm.Summers are characterized by moderate precipitation and the winters are generally marked with high precipitation (Akman, 1999).
Schistidium occurs on nutrient-rich rocks in arctic to temperate regions, but also in warmer parts at higher altitudes.There are about 120-150 species worldwide with ca.50 in Europe (Smith, 2004).
The genus Schistidium is represented by 17 species in Southwest Asia, and 17 are found in Turkey, according to the latest checklists of Turkish bryophytes (Kürschner and Erdağ, 2005;Uyar and Çetin, 2004), and recent floristic catalogues for Southwest Asia (Kürschner and Frey, 2011).In this paper, we present data for the addition of one species (S. sordidum) to the genus Schistidium.The total number of Schistidium taxa in Turkey has reached 18 with the addition of this new record.The description and illustration of the taxon further contributes to the bryoflora of Turkey and Southwest Asia.

MATERIALS AND METHODS
The moss specimen was collected from the Korhan plateau of Ağrı Mountain in March 2010 (Fig. 1).The sample was examined in the laboratory and identification was performed by consulting keys (Nyholm, 1998;Ignatov et al., 2009).The status of S. sordidum was evaluated by reviewing the related literature for Turkey and Southwest Asia (Uyar and Çetin, 2004); Kürschner and Erdağ, 2005;Kürschner and Frey, 2011).The specimens are stored at the Herbarium in the Biology Department, Faculty of Science, Karadeniz Technical University, Turkey (KTUB).Hagen., Nyt mag, Naturvid. 38, 1901.
Plants 1-2 cm high, grow in turfs, dark green and blackish-green above.The leaves are arranged in spiral rows, straight, oblong or ovate, ± strongly concave, obtusely keeled, 1.5-1.8x 0.6-0.8mm, margins entire, usually broadly recurved except at the apex, hair point absent.Costa stout, smooth, ending below apex, in upper and central parts 48-64 μm.Cells in upper part -oval, rhombic and shortly oblong, ± sinuous, 8-12 μm wide; basal cells mostly subhyaline, up to 30-66 μm, sinuous, rectangular.Seta short, capsules very dense and emergent, 2 x 1 mm, exothecial cells strongly thick-walled, peristome 340-450 μm, dark red, spores 14-18 μm (Fig. 2).smooth, unistratose, recurved to near the apex; lamina unistratose, costa in upper and central parts 48-64 μm ………………………………………S.sordidum DISCUSSION S. sordidum belongs to the Apocarpum group Rivulare subgroup (Blom, 1998;Smith, 2004).It is shown in the key below that we can differentiate S. sordidum easily from the other closer Schistidium species in Turkey.S. sordidum resembles S. rivulare but it typically differs in having slender plants, leaves oblong or ovate, rounded at apex, 1.0-1.8(2.1) x 0.5-0.8mm long, margins smooth, unistratose, recurved to near the apex, lamina unistratose, costa in upper and central parts 48-64 μm.In addition, it is especially important that the locality of the place where S. sordidum was found is similar to that of species in other countries.While the number of species belonging to the genus Schistidium is 43 in Russia (Ignatow et al., 2006), with Russia the nearest locality for this species to Turkey, there are now, 17 in Turkey.Therefore, we can assume that this number may increase with further investigation of our country, which has three phytogeographical regions.