Campylopus fragilis (Brid.) Bruch & Schimp., Bryol. Eur.

Campylopus fragilis (Brid.) Bruch & Schimp., Bryol. Eur. View in CoL 1: 164 (fasc. 41. Monogr. 4). 1847. — Dicranum fragile Brid., J. Bot. (Schrader) 1800 (2): 296. 1801. Fig. 4 View Fig .

Plants in loose tufts, green above, yellowish below. Stems 0.5–1 cm, simple, densely foliate. Leaves 4– 5× 0.45–0.55 mm, ovate-lanceolate, widest at1/4 of their length and shallowly narrowed toward insertion, narrowed into long, concolorous subula; costa filling 1/2– 2/3 of leaf width, short excurrent, slightly serrate at tip, in transverse section with very high ventral hyalocysts, filling half of the costa height, guide cells and dorsal stereids, regularly ribbed on dorsal surface due to protruding cells; distal and median laminal cells 10–28×5– 10 µm, quadrate or rhomboidal, thick-walled, sharply differentiated from hyaline, translucent rectangular basal laminal cells; basal laminal cells 50–90(–160)×13–20 µm; alar cells not differentiated, basal marginal cells narrower, in transition zone form rather well differentiated border. Specialized asexual reproduction and sporophytes unknown in Russia.

Differetiation. Campylopus fragilis differs from most other Russian species of the genus in possessing well developed stereids in transverse section of the costa. Although as much as five species in the key above have this trait, D. fragilis is distinguished from most of them by the lack of hyaline hair point, lack of ventral stereids and leaves widest well above the insertion. According to Ignatov et al. (2006), in Russia C. fragilis occurs in the Caucasus, southern Siberia and the southern part of Far East. However, most specimens referred to this species were reidentified as C. schimperi or C. subulatus , excepting the specimen from Kabardino-Balkaria, which suits well to S. fragilis morphologically and which identity was proved by DNA sequencing. Among the other characteristic traits of C. fragilis , asexual reproduction by small leaves in upper leaf axils was not seen in the specimen from Russia. The transverse section of costa in this species shows very high adaxial hyalocysts, occupying ca. half of its height.

Distribution and ecology. Campylopus fragilis has a wide, disjunctive distribution in the areas with rather warm oceanic climate, which, however, might need a revision. In Holarctic it occurs throughout Western and Central Europe, UK and Macaronesia, southern part of Scandinavia, but do not occur or is very rare in East Europe and xeric Mediterranean areas. According to Frahm (2007), in North America it occurs only in two areas: British Columbia in Canada, and Arkansas in the USA. A single Russian collection from the Caucasus is the easternmost in Europe ( Fig. 9 View Fig ); the species might be expect- ed also in warm and wet coastal areas of the Black Sea around Sochi and also in Teberda Nature Park (Karachaevo-Cherkessia), but has not been so far revealed there despite the extensive moss collecting in both areas.

Specimens examined: RUSSIA: Republic of Kabardino-Balkaria, Bezengi Mountain area, Cherek Bezengiysky River valley 1 km upstream Dumala Creek mouth, ca. 1650 m alt., 31 Aug 2004, Ignatov, Ignatova & Kharzinov s.n. ( MHA9011782 About MHA ) .