Campylopus, FROM

KEY TO IDENTIFICATION SPECIES OF THE GENUS CAMPYLOPUS FROM View in CoL FLORA OF RUSSIA:

1. Leaves with hyaline hair point .............................. 2

– Leaves with concolorous point .............................. 3

2. Hyaline hairpoints upward directed, leaf apex often cucullate; laminal cells in basal leaf portion subquadrate, cells in distal portion of leaf lamina elongate, alar region weakly differentiated .... 1. C. atrovirens View in CoL

– Hyaline hairpoints reflexed, leaf apex not cucullate; laminal cells in basal leaf portion laminal cells in basal leaf portion elongate, subquadrate, cells in distal portion of leaf lamina rounded, alar region strongly differentiated .................................. 2. C. introflexus View in CoL

3. Leaves ovate-lanceolate; transverse section of costa with dorsal and ventral stereid bands; exclusively in thermal habitats ............................. 3. C. umbellatus View in CoL

– Leaves lanceolate to linear-lanceolate, rarely ovate lanceolate (but then the plants are alpine); ventral side of costa is formed by hyalocysts/guide cells .. 4

4. Dorsal side of costae is formed by stereids with strongly incrassate walls ....................................... 5

– Dorsal side of costae is formed by substereids with weakly to moderately incrassate cell walls ........... 6

5. Leaves widest at 1/3–1/4 of a leaf length, gradually narrowed to insertion; cells at base of leaf lamina elongate-rectangular, thin-walled, sharply delimit- ed from the subquadrate median laminal cells ....... .............................................................4. C. fragilis View in CoL

– Leaves widest at a leaf base, gradually narrowed distally; cells at base of leaf lamina subquadrate, gradually or rather sharply becoming longer and narrower distally ............................................... [ C. flexuosus View in CoL ]

6. Costae very wide, occupying ca. 3/4 of the leaf base width; alar cells remarkably differentiated, forming inflated group, projecting into costa .. 5. C. gracilis

– Costae narrower, rarely reaching 3/4 of the leaf base width; alar weakly differentiated, not inflated ...... 7

7. Alpine, rarer lowland plants forming dense tomentose tufts ........................................... 6. C.schimperi Lowland View in CoL plants forming loose not tomentose tufts. ............................................................................... 8

8. Dorsal surface of costae smooth .... 7. C. pyriformis View in CoL

– Dorsal surface of costae strongly ribbed due to round projecting cells ................................. 8. C. subulatus View in CoL

Campylopus atrovirens De Not., Syllab. Musc. View in CoL 221.

1838. Fig. 3 View Fig .

Plants in compact pure tufts, blackish proximally, dirty-olivaceous distally. Stems 1.5–3 cm, simple or forked. Leaves 3–5(–6)× 0.45–0.6 mm, straight, narrow lanceolate, ending in a denticulate hyaline hair-point to 0.5 mm long, composed of thick-walled cells; costa filling 1/3–2/3 the leaf base width, in transverse section with ventral hyalocysts of the same height as following guide cells, and dorsal stereids, weakly ribbed on dorsal surface; distal and median laminal cells 25–33×5–8 µm, elongate to vermicular, with incrassate walls, basal laminal cells 20–45×12–20 µm, short rectangular to subquadrate, gradually becoming rhomboid upward, moderately thick-walled, along margins in 3–4 rows narrower, not forming a distinct border; alar cells scarcely to moderately differentiated, composed of weakly inflated, moderately thick-walled cells, hyaline or brown. Specialized asexual reproduction by fragile stem tips. Sporophytes unknown in Russia.

Differentiation. Typical, well developed C. atrovirens is a large (up to 10 cm) black plant growing near cold springs and waterfalls. However, Russian specimens, both from the Caucasus and Kamchatka, are remarkably smaller and have dirty olivaceous coloration. At the same time, they are distinguished from all other Russian species of Campylopus due to the presence of straight hyaline hair points. According to Frahm (2007), leaves of C. atrovirens occasionally may lack hyaline hair points. In such cases, this species can be recognized by having leaves with cucullate apices and long, vermicular upper laminal cells.

Distribution and ecology. Campylopus atrovirens has predominantly Holarctic, amphioceanic distribution. It

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I occurs throughout UK, in south-western Scandinavia, mountains of Central and Western Europe , an isolated locality in the Caucasus, in Kamchatka Peninsula ( Fig. 9 View Fig ) and Japan, in Labrador, Newfoundland, and Appalachian Mts in North Carolina , along the western coast of North America, from Washington to Alaska, and in a few localities in the middle Aleutians. Russian localities of the species are remarkably distant from the closest areas where the species grows and originate from the areas with volcanogenic ecotopes. In the Caucasus it was collected in lava fields of Elbrus Mt. in Kabardino-Balkaria, in Kamchatka in the thermal fields near Pauzhetka Settlement (south of the peninsula) .