Orthotrichiaceae. Genus Lewinskya

1.Exostome teeth when dry erect or spreading at right angles to capsule mouth; endostome absent or present; plants saxicolous, rarely corticolous 2

— Exostome teeth when dry reflexed and/or appressed to capsule wall; endostome present; plants corticolous, rarely saxicolous 7

2.Capsules immersed or emergent7. L. rupestris

Lewinskya rupestris can be recognized by combination of large plant size; immersed to emergent, smooth capsules; exostome teeth when dry spreading at right angles to capsule mouth; reduced endostome; and calyptrae with dense, especially long, ascending hairs that mostly exceed the top of calyptrae. Lewinskya rupestris is a temperate montane species present in most European countries; northern and southern Africa; Central Asia; the Western Hemisphere from Alaska to Bolivia; and SE Australia, Tasmania and New Zealand. In Russia the species is widespread in the Caucasus and southern Siberia (Altai Mts, Sayans, Salair Range, Kodar Range) but somewhat rare northward in the Kola Peninsula, Karelia, southern Urals, subarctic eastern Siberia (Anabar Plateau), Yakutia (Orulgan Range) and Chukotka. Although L. rupestris mostly grows on siliceous rocks, in places where it is especially common it also occurs on branches and twigs.

— Capsules short- or long-exserted 3

3.Endostome segments erect when dry, filiform, smooth, ± half exostome length, fragile, often broken off or absent 4

— Endostome segments incurved when dry, linear, papillose, as long as exostome teeth, sturdy, usually persistent 5

4.Capsules gradually tapered to setae; neck distinct; capsule slightly furrowed in upper part 6. L. pylaisii

Lewinskya pylaisii can be recognized in field by its short-lanceolate leaves; short- to somewhat long-exserted capsules that are slightly ribbed in upper part and gradually narrowed to the setae; well-defined capsule necks; 8 pairs of exostome teeth that cleft with age; exostome teeth when dry spreading to reflexed at right angles to the capsule mouth; and endostomes usually absent. Lewinskya laevigata and L pylaisii can be confused because both are mostly saxicolous plants and have somewhat short leaves, smooth, exserted capsules, and no endostomes. But, L. laevigata differs from L. pylaisii in capsule form (abruptly narrowed vs. gradually narrowed to setae); exostome teeth number (8 pairs vs. 16 with teeth free or slightly connate at base), and also never reflexed vs. varying from star-like to reflexed. Lewinskya pylaisii is a widespread, amphioceanic Arctic/boreal species present in Fennoscandia and the Baltic Sea islands, Iceland, Greenland, Svalbard, Canadian Atlantic Provinces, Yukon, Subarctic Alaska, and along the western coast of North America from the Aleutians to northern California. In Russia this species has a bicentric distribution: the coastal areas and islands of the Kola Peninsula (Barents and White Seas) and Kamchatka Peninsula and Commander Islands (Bering Island) in the Russian Far East. Lewinskya pylaisii is a moss of humid environments that grows on siliceous rocks near seashores.

— Capsules more or less abruptly narrowed to setae, neck absent; capsule smooth in upper part 5. L. laevigata

Lewinskya laevigata differs from other species of Lewinskya, as well as the saxicolous Orthotrichum anomalum and Ulota hutchinsiae in having the following combination of features: exserted, somewhat short, smooth capsules; usually 8-pairs of exostome teeth that are erect or spreading at right angles to capsule mouth when dry; and endostome mostly absent. For the differences between L. pylaisii and L. laevigata see discussion under L. pylaisii. Lewinskya laevigata has a suboceanic holarctic distribution with localities in Europe (common in Scandinavia and Iceland), throughout western North America, and a few localities in temperate Asia. In Russia the species is similar to L. pylaisii in favoring humid, marine environments and having a bicentric distribution: southern shores of the Kola Peninsula (Kandalaksha State Reserve) and a few areas in the southern, temperate Russian Far East. These southern Far East collections, although morphologically close to L. laevigata appear phytogeographically odd, and further study may find they represent a cryptic species. Most records of Lewinskya laevigata in northern Asia (Anabar Plateau, Yakutia and Chukotka) represent either L. iwatsukii or a putative, undescribed species of close to L. iwatuskii.

5.Leaves blunt or acute; upper leaf cells with low, simple papillae[Ulota hutchinsiae]

— Leaves acuminate; upper leaf cells with high, forked papillae 6

6.Capsules smooth in upper part 4. L. iwatsukii

Lewinskya iwatsukii differs from all other Lewinskya species in having the following combination of features: large plants; narrow, lanceolate leaves; high forked leaf cell papillae; exserted capsules; and exostome teeth spreading at right angles to the capsule mouth when dry. In addition, L. iwatsukii differs from other large, saxicolous Lewinskya species in having persistent endostomes that are ± as long as the exostome teeth, and from corticolous species of Lewinskya, e.g. L. elegans, in having leaf cells with forked papillae. Lewinskya iwatsukii was originally described from Japan, but at present is known from the Himalayas, India, Siberia, Russian Far East, the Caucasus and the Polar Ural area. It is widespread and especially abundant in Arctic East Siberia, Yakutia and Chukotka where it grows on basic and calcareous sedimentary rocks, larch trunks, rocky soil, pebbly creek bars, in open tundra communities, and occasionally on Populus, Salix, and Larix. Lewinskya iwatsukii displays considerable variation in capsule morphology, particularly in the the upper parts of the capsules. Our preliminary data on the species indicate it may harbor one or many cryptic species.

— Capsules 8-ribbed in upper part 4. L. cf. iwatsukiikilliasii”morphotype)

Arctic plants similar to L. iwatsukii, but with capsules 8-ribbed distally are referred here tentatively to L. cf. iwatsukii, “killiasii”morphotype. Orthotrichum killiasii Mull. Hal., described from Switzerland was accepted for Russian Arctic by Abramova et al. (1961), but later usually included in synonymy of L. speciosa. Preliminary results of our molecular phylogenetic studies indicate that this species might merit resurrection.

7(1). Capsules immersed to shortly emergent 7

— Capsules emergent or exserted 11

8.Capsules smooth when dry 9

— Capsules ribbed when dry 10

9.Leaves acuminate, rarely acute; exostome teeth 16; endostomial segments 16, margins sinuose in outline 10. L. striata

Lewinskya striata is distinguished from other Lewinskya species by the combination of deeply immersed, pale, smooth capsules; 16 exostome teeth; and 16 fairly broad, lanceolate endostomial segments. Curiously, sometimes specimens have emergent capsules. Lewinskya transcaucasica differs from L. striata in having shortly emergent rather than immersed capsules; 8-pairs of orange rather than 16, pale exostome teeth; and having longitudinal crests rather than papillae on the lower, inner (ventral) exostome surface. Lewinskya striata has a holarctic distribution but is more common in western Eurasia and western North America. Except for northern Scandinavia the species is widespread in western Europe and also occurs in North Africa, Turkey, Pakistan, China, Japan, and western North America from southern Alaska to California. In Russia it is the most common species of the genus in Kaliningrad Province and some parts of the Caucasus. It also oρρurs sporadically in the Altai and is known from a single locality in Volgograd Province). Lewinskya striata occurs in shaded, humid as well as exposed, dry habitats growing on Fagus, Carpinus, Betula, Padus, Salix and Sorbus.

— Leaves rounded, obtuse or acute; exostome teeth 8-paired; endostomial segments 8, margins entire in outline [L. vicaria]

Lewinskya vicaria (Laz.) F. Lara, Garilleti & Goffinet was described from the Fergana Valley in central Tian-Shan and is still known only from the type specimens. This species was discussed by Lewinsky-Haapasaari (1994). Lewinskya vicaria is similar to L. transcaucasica in having 8 pairs of exostome teeth and 8, entire margined endostomial segments. But, it differs in having obtuse to rounded leaf tips; upper leaf margins distinctly crenulate due to protruding papillae; and immersed capsules.

10.Capsules below mouth red; endostome segments 16 2. L. dasymitria

Lewinskya dasymitria is similar to L. transcaucasica inhaving shortly emergent capsules; 8 pairs of irregularly split exostome teeth; and 16, entire-margined endostome segments. Itdiffers from L. transcaucasica as well as all other species of the genus in having capsules that are dark red and distinctly ribbed below the mouth. Somewhat similar broadly rimmed capsules also occur in L. rupestris, but that species differs from L. dasymitria in lacking an endostome. This rare moss was described from Xizang (Tibet) and is also known from from the Chinese provinces of Yunnan, Sichuan and Shanxi. In Russia the species occurs at 450–600 m elev. in the Altai Mts near Teletskoe Lake. It grows on Sorbus in fir forests and Rhododendron twigs in birch forests.

— Capsules concolorous throughout; endostome segments 8 1. L. affinisfastigiatum” morphotype]

Lewinskya affinis is here considered in a broad sense to include L. affinis var. fastigiata. It differs from L. affinis s. str. in having smaller plants; capsule ribs (4–6 cells wide); immersed, urceolate capsules that are distinctly contracted below mouth; and sparsely hairy to smooth calyptrae. In contrast L. affinis s. str. has larger plants; weaker capsule ribs; emergent, cylindric, capsules not contracted below mouth; and moderately hairy calyptrae. In Russia the L. affinis var. fastigiata morphotype occurs in Eastern European Russia (Belgorod Province) and the Western Caucasus region.

11(7). Capsules emergent; setae equal to or shorter than capsules 12

— Capsules exserted; setae longer than capsules 17

12.Mature capsules with 8 distinct, dark ribs and deeply furrowed along their entire length 13

— Mature capsules smooth or with 8 narrow, short ribs, and not or slightly furrowed above 14

13.Capsules slightly emergent; exostome teeth not or slightly perforated along median tooth line or fenestrate above 1. L. affinis

Lewinskya affinis is closely related to L. sordida but differs in having mostly acute leaves; slightly emergent capsules; paler exostome teeth not or slightly perforate along median lines; and pale, naked or nearly naked, campanulate calyptrae. In contrast L. sordida has acute to acu­mi­nate leaves; strongly emergent to exserted capsules; typically bright exostome teeth perforated along median lines and fenestrate above; and golden, sparsely hairly, mostly conic calyptrae. Lara et al. (2009b) also found the two species differed in endostome ornamentation: L. sordida weakly ornamented, segments translucent; L. affine more strongly ornamented with striae and papillae. In European Russia L. affinis has often been confused with L. speciosa because both species have strongly ribbed capsules. But, L. affinis differs from the widespread L. speciosa in having longer capsule ribs (extending nearly the length of the capsules); shorter setae; and long-rostrate opercula. Lewinskya affinis is widespread in Europe and Macaronesia, it also occurs in northern and eastern Africa, western and Middle Asia, north India, China, Japan, temperate as well as continental areas of North America. In Russia the species is restricted to European Russia (western provinces mostly within the steppe zone) and the Caucasus. There are many records of the species from more northern areas in the forest zone (Murmansk Province, northeastern European Russia, and the Urals). But, in fact these collections represent L. speciosa or L. elegans. Records of the species from the Russian Far East need further study before their identity can be confirmed. Lewinskya affinis grows on the bark of deciduous trees.

— Capsules strongly emergent to exserted; exostome teeth perforated along median lines and fenestrate above 8. L. sordida

Lewinskya sordida is closely related to L. affinis but differs in setae length (capsules strongly emergent to exserted vs. capsules slightly emergent) and exostome teeth form (fenestrate above vs. entire above). However, at times (especially in the Caucasus, where both species occur) they can be difficult to separate (see comments under L. affinis). Lewinskya sordida is sometimes confused with L. elegans because both have emergent to exserted capsules; reflexed exostome teeth; and eight well-developed endostome segments. In L. elegans, however, the capsules are longer, not contracted below mouth when dry, and the endostome segments are pale, not translucent, and papillose. In contrast L. sordida has distinctly ribbed capsules that are contracted below mouth when dry and translucent, smooth or nearly so endostome segments. Lewinskya sordida is very polymorphous species and in fact likely represents the group of related taxa. In particular, in southern part of Russian Far East it varies in position of capsules, exostome teeth fenestration, number of segments and calyptrae characters. In addition, a Caucasian morphotype differs from Far Eastern ones. Furthermore, due to underestimating variability of L. pylaisii, which has parallel forms with L. sordida, its marginal morphotypes are often referred to the latter species. Recently this problem was essentially addressed by Vitt (2017) for Pacific Region, but in european Arctic it is still actual. Lewinskya sordida is primarily a cool temperate to subarctic species distributed in eastern Eurasia and eastern North America but it also occurs at higher latitudes (Alaska, western Greenland, south Siberia) as well as the Caucasus. It has been reported from Arctic & Subarctic European localities (Svalbard, Kola Peninsula) but these reports are in need of confirmation. In eastern North America it is especially common in New England and extends as far north as Labrador and Newfoundland; in East Asia it is known from Japan, Korea, and China. In Russia L. sordida is the most abundant Lewinskya species (as well as Orthotrichum s.l. species) in the Russian Far Eas, an area dominated mostly by the genus Ulota. In addition, it occurs in the mountains of South Siberia (Sayans and Altai), and in the vicinity of LakeBaikal. This common forest zone species is typically found in open forests or at forest edges in relatively humid areas, including populated places. It grows on the trunks/twigs of many trees and shrubs. Ignatov & Lewinsky-Haapasaari (1994) found that in the Altai L. sordida and L. elegans were nearly equally common and this appears to be case in the Eastern Sajan Mts. However, L. sordida is gradually replacing L. elegans to the east.

14.Capsules smooth 15

— Capsules ribbed above 16

15.Capsules cylindric, exostome teeth in 8-pairs, never cleft; endostome segments 8, margins smooth 4. L. elegans

Lewinskya elegans is usually treated as a synonym of L. speciosa in recent European and Russian handbooks and check-lists. However, Vitt & Darigo (1997) considered them distinct species. In northern European Russia, east Caucasus and Siberia collections in this complex have the smooth capsules that correspond to L. elegans, while most plants from central European Russia have the distinctly 8-ribbed capsules that correspond to L. speciosa s. str. Indeed, recent molecular phylogenetiρ study of this complex support this view of the two taxa. Lewinskya elegans differs from other Russian species of Lewinskya by following combination of features: upper leaf cells with simple papillae; capsules cylindric, smooth, emergent to short exserted; exostome teeth in 8 pairs, reflexed, pale-orange; and endostome segments 8, moderately wide, curved inward when dry, pale, papillose. The world distribution of the species is still insufficiently known because of the confusion between L. elegans and L. speciosa; in North America it occurs between the 40th and 50th parallels in Canada in the boreal and hemiboreal zones; in eastern North America it is found in the Atlantic States and the Great Lakes area; and between the 50th and 60th parallels in western North America, but not extending to the Pacific coastal areas. In Russia L. elegans is widespread and common in northern European Russia, northward to the southern taiga subzone; the eastern Caucasus (in western Caucasus L. speciosa s. str. occurs); western, eastern and southern Siberia (except the Arctic), and from scattered localities in the southern Russian Far East. In the eastern Russian Far East it is gradually replaced by L. sordida.

— Capsules ovate-oblong; exostome teeth in 8-pairs, often cleft; endostome segments 8 or 16, margins mostly irregularly beaded to subentire 11. L. transcaucasica

Morphologically, L. transcaucasica can be considered an intermediate species between L. striata and L. elegans because of the presence of emergent to shortly exserted, smooth capsules; exostome teeth mostly paired but not attached to one another; and 8–16 endostome segments. It can be separated from other Russian Lewinskya species by the following combination of features: capsules emergent to exserted, shortly oblong or ovate, smooth or nearly so; and exostome teeth orange, mostly in 8 cleft pairs with remarkable crests on the inner (ventral) surfaces, 8 to 16, wide endostome segments with bead-like or subentire margins. For the differences between L. transcaucasica and L. vicaria/L. dasymitria see disρussions under those species. Lewinskya transcaucasica was described from Georgia (Eckstein et al., 2017) and is now known from Dagestan, the Altai, Kotuyskoe Plateau (SE Taimyr), Republic of Buryatia, Transbaikalia, Amur Province and the upper Bureya River, Khabarovsk Territory (Fedosov et al., 2017b). The siberian collections of L. transcaucasica were previously identified as L. striata. Lewinskya transcaucsica is a corticolous moss found on aspen, alder, birch, spruce, bird cherry, etc. at moderately high (400–1100 m) elevations. Both L. striata and L. transcaucasica occur in the Altai area, but the first species inhabits moist, shady forests, while L. transcaucasica occurs in more xeric, exposed environments.

16.Capsules concolorous throughout; endostome segments 8; widespread in European Russia 9. L. speciosa

In Russia L. speciosa was until recently treated in a broad sense to include L. elegans. Both are widespread, epiphytic species with exserted capsules, superficial stomata and narrow endostome segments. Vitt & Darigo (1997) recognized both as distinct species (see discussion under the latter species), and their treatment is followed here. Lewinskya speciosa differs fromL. sordida and L. affinis in having shorter and less strongly differentiated exothecial ribs; pale exostome teeth; and papillose, non-translucent endostome segments. It differs from L. iwatsukii in leaf cell papillae form (simple vs. forked) and setae length (capsules emergent to short-exserted vs. long-exserted). Lewinskya speciosa is a holarctic species mostly associated with cool, temperate and hemiboreal zones; towards the southern end of its range it is a montane species. In European Russia L. speciosa is the most widespread, common species of the genus in broadleaved forests but becomes rarer northward, in south taiga subzone, being substituted by L. elegans, and southward, in steppe zone. All specimens named L. speciosa from Siberia and the Far East actually represent L. elegans or L. cf. iwatsukii.Lew­ins­kya speciosa is a corticolous species often abundantly growing on most trees/shrubs (including introduced ones) in middle European Rus­sia, as well as recently fallen logs, boulders, and concrete. The species seems to prefer mode­ra­tely shady conditions and when encountered is usually found on multiple rather than single trees.

— Capsules dark, orange-brownish below mouth; endostome segments 16; rare central Asian species2. L. dasymitria

17(11).Capsules very long and narrowly cylindric, endostome segments nearly as wide as exostome teeth, concolorous with them, bright-red 12. L. vladikavkana

Lewinskya vladikavkana can be recognized by the following combination of features: setae 2–3(–4) mm long; exceptionally narrow-cylindric, nearly smooth or ribbed distally capsules; and mostly bright-red endostome segments that are almost as broad as the exostome teeth. In Russia L. vladikavkana is common at elevations up to 1000 m in the central and eastern Caucasus from Kabardino-Balkaria to Dagestan (Ignatov et al., 2010), and in the northern Altai Mts. Plants from the Altai differ from Caucasian plants in having somewhat larger spores (24–29 vs. 21–25 mm). Long considered a Russian endemic, L. vladikavkana is now known from Kazakhstan (Hradilek et al., 2011) and northeast Turkey (Lara et al., 2010). The Chinese and Himalayan L. hookeri (Mitt.) F.Lara, Garilleti & Goffinet is similar to L. vladikavkana in peristome structure and in having exserted, narrowly cylindric capsules, but differs in having larger spores, (25–)35–53 vs. 21–29 mm, and flexuose leaves with recurved margins. L. vladikavkana grows in the same habitats as L. striata, L. elegans andL. sordida: on trunks/twigs of Betula, Padus, Salix, Abies, Caragana and Sambucus at moderate elevations.

— Capsules wider, cylindric, ribbed or smooth; endostome segments much narrower and distinctly paler than exostome teeth, pale orange or translucent or endostome rudimentary 18

18.Leaves short-lanceolate, acute; capsules gradually narrowed to setae; young exostome teeth when dry spreading at right angles to capsule mouth, later cleft into 16 teeth; endostome segments filiform, mostly broken off 6. L. pylaisii

— Leaves lanceolate to linear-lanceolate, acuminate; capsules more or less abruptly narrowed to setae; exostome teeth reflexed when dry, not cleft when old or, if spreading at right angles to capsule mouth, endostome segments broad, persistent 19

19.Capsules urceolate, contracted below mouth when dry, with 8 strongly developed ribs and narrow furrows; exostome teeth mostly orange to red, strongly perforated above 8. L. sordida

— Capsules cylindric, not contracted below mouth when dry, smooth or slightly ribbed above, with narrow ribs and wide furrows; exostome teeth pale yellow, not or slightly perforated above 20

20. Capsules well exserted on rather long, (2–)2.5–5 mm, setae; mostly saxicolous 5

— Capsules shorther exserted, setae 1.5–2(–2.5); corticoous 21

21.Capsules 8-ribbed above 9. L. speciosa

— Capsules smooth 3. L. elegans