Grimmiaceae. Genus Grimmia

1. Leaves soft, broadly ovate; leaf cells 12–25 µm wide — 23. G. mollis

Mountain species sporadically distributed in Russia in Kola Peninsula, Polar and North Urals, the Caucasus, Siberia, and Russian Far East. It grows in forest and alpine regions on moist rocks and soil along water courses, often in temporary brooks below melting snowbeds.

— Leaves rigid, linear, ovate-lanceolate or ovate; leaf cells 6–15 µm wide — 2
2. Capsules immersed, setae 0. 3–0. 5(–1. 0) µm — 3
— Capsules emergent to exserted, setae longer than 1 mm, or plants sterile — 9
3. Plants robust; leaves (2. 0–)2. 5–4. 0 µm long, ovate at base and narrowed above to long-lanceolate acumina — 34. G. pilifera

This species is known in Russia only east of the Urals, mainly in the southern part of Russian Far East where it is the most common species of the genus. It also extends northward to Chukotka and westward to the Altai Mts. A species of the forest region (up to 1900 m a. s. l. in Altai Mts. ), it grows on shady acidic and neutral rocks. Its main diagnostic characters include large plants, absence of stem central strand, shouldered leaves above ovate bases, apices with long acumina and immersed capsules.

— Plants small to medium-sized; leaves 1. 0–2. 0(–2. 5) µm long, ovate to lanceolate — 4
4. Leaves canaliculate throughout; leaf lamina bistratose in upper 2/3; costae weakly differentiated, flattened or semi-elliptical in transverse section — 5
— Leaves keeled above, canaliculate below; leaf lamina mostly unistratose or bistratose at margins in 1–5 cell rows, rarely mostly bistratose above (G. anodon); costae strongly differentiated, semi-circular in transverse section — 6
5. Capsules symmetric; setae erect, centrally attached; usually on calcareous substrates — 29. G. tergestina

A widespread xeric species in Russia rather common in the Caucasus, Altai and Sayan Mts. and occurring sporadically in the Urals, southern Taimyr, Yakutia, and Russian Far East. It grows on dry calcareous rocks in forest and subalpine regions (up to 2250 m a. s. l. in Altai Mts. ), and occasionally on steppe slopes in premafrost zone of Siberia. It can be recognized by its enlarged perichaetial leaves with hyaline marginal border at base to almost the whole leaf except the costa in the innermost ones, immersed symmetric capsules on straight, centrally attached setae and canaliculate, distally bistratose leaves with weakly differentiated costae. However, when sporophytes are absent, which is often the case for G. tergestina, it is practically impossible to separate from G. poecilostoma. If plants lack sporophytes, only their different ecological preferences can be used to separate the two species (calcareous vs. acidic substrates).

— Capsules asymmetric, ventricose; setae sigmoid, excentrically attached; mostly on acidic or neutral substrates — 28. G. poecilostoma

In Russia this species is found in the Caucasus, Altai, southern Taimyr, Yakutia and Transbaikalia. It grows on dry acidic rocks (ijolite, sienite, granite, sandstone) in all altitudinal zones (up to 2800 m a. s. l. in the Caucasus). Its gametophytes are indistiguishable from those of G. tergestina (see comments under that species for their gametophytic differentiation). The species can be recognized by its immersed ventricose capsules on curved, excentrically attached setae, presence of peristome, canaliculate leaves with distally bistratose leaf lamina and weakly differentiated costae.

6. Capsules symmetric; setae erect, centrally attached — 7
— Capsules asymmetric, ventricose; setae sigmoid, excentrically attached — 8
7. Leaf margins plane; stem leaf basal marginal cells with uniformly thin longi­tudinal and transverse walls — 20. G. triformis

A very rare mountain species known in Russia from three localities: 1) Altai Mts. , near the tim­berline in Pinus sibirica forest, 2050 m a. s. l. , on acidic rocks; 2) southern Taimyr, in stream canyon, on rocks rich in ferrum; 3) Kamchatka, slope of Ushkovsky Volcano, at 1070 m a. s. l. , on rock in mountain tundra. Grimmia triformis is very similar to G. donniana in leaf shape, and in having plane leaf margins as well as uniformly thin-walled, basal leaf cells; they can be distinguished only when capsules are present (common in both species): immersed in G. triformis with setae less than 0. 5 µm long, and emergent to exserted in G. donniana with seta 1. 5–3 µm long.

— Leaf margins recurved; stem leaf basal marginal cells with thin longitudinal but thick transverse walls — 15. G. capillata

A rare xeric species found twice in Russia: 1) in SE Altai Mts. , in deserted steppe in Chuya River Valley, on loamy soil, and 2) in southern Buryatia, on rocks on forested slope. Its diagnostic features include immersed symmetric capsules on centrally attached straight seta, unistratose leaf lamina, narrow, well differentiated costae and comparatively long hair-pointed upper/perichaetial leaves with hair-ponts considerably widended at base.

8. Peristome absent — 13. G. anodon

A widespread xeric species that is rare in lowland provinces from Karelia to Kalmykia, sporadic in the Caucasus and Urals, very common in the Altai Mts. , rather frequent in southern Taimyr and also found in central parts of Krasnoyarsk Territory, Chukotka and Yakutia. It grows in the lowlands and in all altitudinal mountain zones mainly on dry calcareous rocks. When sporophytes are present it can be recognized by its immersed ventricose capsules on short, curved, excentrically attached setae, absent peristome and flat, mammilate opercula. When sporophytes are absent its small plant size, ovate leaves, absence of hair-points on lower leaves and short hair-points on upper leaves, partially bistratose upper leaf lamina and narrow, well differentiated costae are helpful in recognizing the species.

— Peristome present — 14. G. plagiopodia

In European Russia this species is known from a few localities in the southern lowland provinces and Tatarstan Republic as well as in the Caucasus and the Altai Mts. It grows on sandstone, limestone, marl rocks and shell gravel in rather dry conditions from sea level to ca 2200 m a. s. l. (in Altai Mts. ). Its diagnostic characters include consistently unistratose leaf lamina, narrow, well differentiated costa, immersed symmetric capsules on short, straight, centrally attached setae and presence of a peristome.

9(2). Stem leaf basal marginal cells with uniformly thin longitudinal and transverse walls — 10
— Stem leaf basal marginal cells with thin longitudinal but thick transverse walls — 13
10. Leaf margins plane, never recurved; opercula low conic-mammillate — 19. G. donniana

A mountain species widely distributed in Russia: common in the Kola Peninsula (most frequent species of the genus in Khibiny Mts. ); locally abundant in some areas of southern Taimyr and sporadic in North and Polar Urals, Yakutia, Magadan Province, Kamchatka, and Altai; found once in the Caucasus (on Elbrus Mt. , at 2800 m a. s. l. ). It grows in forest and alpine montane regions up to 3800 m a. s. l. , mainly on rather dry acidic and neutral rocks. Grimmia donniana can be recognized by its comparatively widely keeled leaves, plane leaf margins, rather long leaf hair-points, basal stem leaf cells with uniformly thin longitudinal and transverse walls and capsules with low conic-mammilate operculum.

— Leaf margins recurved below on one or both sides; opercula shortly beaked — 11
11. Leaves long, narrow, linear-lanceolate, strongly flexuose to almost crisped when dry; basal juxtacostal cells with thick, porose to nodulose longitudinal walls and very thin transverse walls — 18. G. incurva

A widespread species in Russia, common in the Kola Peninsula, Urals, Caucasus and Altai Mts. , but occurring sporadically in Taimyr, Yakutia, Sayan Mts. , Transbaikalia and Russian Far East, from Chukotka to Primorsky Territory. It grows in mountain areas in all altitudinal zones but is more frequently above timberline (up to 3400 m a. s. l. ) on acidic and neutral rocks (granite, sandstone) in dry and mesic conditions. It can be separated from other species of the genus by its linear-lanceolate leaves that are flexuose to crisped when dry and have basal marginal cells with uniformly thin longitudinal and transverse walls. Slender alpine forms with less flexuose leaves can be recognized by leaves that have comparatively strong costae, narrow distal laminae, thick-walled, porose basal juxtacostal cells and thin-walled basal marginal cells.

— Leaves ovate-lanceolate or lanceolate, slightly flexuose when dry; basal juxtacostal cells with moderately thickened, slightly porose longitudinal walls and thin transverse walls — 12
12. Leaves with long hyaline hair-points (mostly > 0. 3 mm); setae arcuate when wet — 21. G. fuscolutea

This species occurs sporadically in mountain areas throughout the world. In Russia it is known from a few localities in the Caucasus, Altai Mts. , Buryatia and Kamchatka. It grows in forest and alpine regions on acidic rocks up to 3350 m a. s. l. Its brownish plants, strongly sinuose upper leaf cells and uniformly thin-walled basal marginal cells in combination with slightly furrowed capsules on arcuate setae and opercula with short obtuse beaks are helpful for species recognition.

— Leaves with very short hyaline hair-points (usually < 0. 3 mm) or muticous; [setae erect when wet] — 17. G. elongata

A mountain species occurring sporadically throughout the world. In Russia it is known from only one locality in Subpolar Urals and in two closely spaced localities in Kamchatka. It grows on acidic rocks above timberline, at 500–1500 m a. s. l. Its main diagnostic characters include brownish plants, and sharply, narrowly keeled leaves with consistently short, hyaline hair-points and uniformly thin-walled basal marginal cells. It differs from G. fuscolutea in its sexual condition (dioicous vs. autoicous) and in having leaves with weakly sinuose upper cells and shorter hair-points. There are also good sporophytic differences between these species (straight vs. arcuate setae and smooth vs. slightly furrowed urns), but sporophytes are lacking in Russian collections of G. elongata.

13(9). Leaf margins plane — 14
— Leaf margins recurved below on one or both sides — 21
14. Upper leaf cells bulging — 15
— Upper leaf cells not bulging — 16
15. Leaves strongly plicate; upper leaf cells with scattered papillae — 27. G. caespiticia

This species is rather frequent in the Caucasus and occurs sporadically in the mountains of southern Siberia (Altai and West Sayan). It grows on acidic and neutral rocks above timberline in open mesic sites. It differs from other species of the genus in having small, glaucous plants and strongly plicate leaves with plane margins, bistratose laminae and bulging, papillose upper leaf cells.

— Leaves not or weakly plicate; upper leaf cells without papillae — 25. G. alpestris

A mountain species rather frequent in the Caucasus, mountains of southern Siberia, Kamchatka and Commander Islands. Also known from single localities in Sakhalin, South Urals and Kola Peninsula. It grows on acidic and neutral rocks, mainly in alpine regions, rarely below timberline and up to 3800 m a. s. l. It is similar to G. caespiticia in having small plants with partially bistratose upper laminae and bulging leaf cells, but it has smooth or weakly plicate leaves and leaf cells that always lack papillae.

16. Costae terete, prominent both dorsally and ventrally, round in transverse section — 36. G. teretinervis

This species is known from the Urals, the Caucasus, southern Taimyr, Yakutia and the vicinity of Krasnoyarsk City. It grows on dry calcareous rocks mainly at low altitudes (up to 2000 m a. s. l. in the Caucasus).

— Costae semi-terete, prominent dorsally, not prominent ventrally, semi-circular or semi-elliptic in transverse section — 17
17. Leaves keeled above; costae strongly differen­tiated, strongly prominent dorsally, semi-circular in transverse section, with 2 ventral epidermal cells — 24. G. montana

A mountain species found in Russia in two localities: Karelia and the Caucasus (Karachaevo-Cherkessian Republic). It grows on forest rock outcrops (Karelia) and on granite boulders in alpine/subalpine regions (Caucasus). It can be recognized by its keeled leaves that have plane margins, bistratose, smooth upper laminae and dorsally prominent costae that in transverse section have two ventral epidermal cells.

— Leaves concave above; costae weakly differentiated, slightly prominent or flattened dorsally, semi-elliptical in transverse section, with (2–)3–6 ventral epidermal cells — 18
18. Stem leaf basal marginal cells oblate, opaque — 30. G. laevigata

This species occurs in arid regions through­out the world. In Russia it is common in xeric areas in the Caucasus and occurs sporadically in the steppe regions of European Russia, South Urals, Altai and West Sayan Mts. , Baikal Lake area and Transbaikalia. It grows on dry, mainly neutral rocks in open sites, mostly at low and middle altitudes, with a single record from ca. 3000 m a. s. l. in the Caucasus. Triangular-ovate leaves with numerous oblate cells along the basal leaf margins are unique to this species.

— Stem leaf basal marginal cells quadrate or rectangular, pellucid — 19
19. Leaves muticous, apices cucullate — 32. G. unicolor

Mountain species, sporadic in the Caucasus, known from singular records in Urals and Karelia, rather frequent in Altai Mts. , extends eastward to the Baikal Lake area and found once in southern Taimyr. Grows on acidic rocks, mainly above tree-line, at 1700–3000 m a. s. l. , rarely in the forest belt.

— Leaves hyaline hair-pointed, apices acuminate — 20
20. Leaves ovate at base tapering into long, narrow, lanceolate acumina; perichaetial and stem leaves similar; capsules exserted — 31. G. ovalis

This species is moderately frequent in the Caucasus and in southern Siberia, sporadic in central European Russia and known from a few records in the Urals, Krasnoyarsk Territory, Yakutia and Primorsky Territory. It grows on dry mainly siliceous rocks, rarely on calcareous substrates, in shady and open sites at lower and middle altitudes (up to 2500 m a. s. l. in Altai Mts. ). It is recognized by the combination of concave leaves with long, narrow acumina, plane margins, bistratose upper cells and weakly differentiated costae. G. longirostris is separated from it by the presence of leaves with partially recurved leaf margins and reniform (in transverse section) costae that strongly project dorsally.

— Leaves ovate at base, tapering into short, rather wide acumina; perichaetial and stem leaves different, perichaetial leaves filmy at base or in lower 2/3, with very thin-walled basal cells; capsules immersed — 28. G. tergestina
— 29. G. poecilostoma
[These two species can not be reliably separated without sporophytes].
21(13). Gemmae present — 22
— Gemmae absent — 27
22. Gemmae on leaf apices — 23
— Gemmae on branched stalks at leaf base on ventral side of costa, or sessile/subsessile on lamina or costa — 24
23. Leaf cells with longitudinal cuticular ridges (papillae-like in transverse section) on both surfaces; gemmae yellowish — 1. G. anomala

A sporadic circumholarctic species known in Russia in the Caucasus, South Urals, Kola Peninsula, Altai, Kuznetsky Alatau, and Kamchatka. It grows in forest and subalpine mountain regions in mesic conditions on acidic and basic rocks. It can be recognized by its striolate leaves that have eroded, often truncate apices with easily detached, multicellular gemmae.

— Leaf cells smooth; gemmae red-brown or orange — 2. G. hartmanii

This species is frequent in the Caucasus, rare in NW European Russia and South Urals, sporadic in Russian Far East from Kamchatka to Kuril Islands and Primorsky Territory; once collected in southern Taimyr. It grows on acidic and neutral rocks in forest regions. Its diagnostic features include comparatively large plants with stems often curved above, leaves with very short hyaline hair-points and large, red-brown or orange multicellular gemmae on the leaf apices.

24. Leaves contorted to crisped when dry; leaf cells with strongly thickened walls; gemmae subsessile on dorsal side of costa at base of upper leaves — 10. G. torquata

This species is common in Murmansk Province and Karelia, and occurs sporadically in Chukotka, Kamchatka and southern Taimyr. It was recently found in the Caucasus, SE Yakutia and Khabarovsk Territory. In the northern part of its range, G. torquata grows at low altitudes on wet acidic rocks, often on vertical walls, and occasionally on soil in tundra (Vrangel Island). In southern areas it is restricted to the alpine mountain regions where it grows on wet cliffs. The combination of strongly contorted leaves, thick-walled leaf cells and multicellular gemmae on dorsal side of costa makes this species recognizable.

— Leaves straight or slightly flexuose when dry; leaf cells with moderately thickened walls; gemmae on branched stalks on ventral side of costa at leaf base or sessile on both sides of lamina and costa — 25
25. Gemmae sessile on both sides of laminae and costae — 8. G. trichophylla

This species was reported from Kaliningrad Province, Crimea and the Caucasus. We haven't seen any correctly identified specimens from these regions; however, the species will be likely found in Russia. It is most similar to G. muehlenbeckii in appearance and differs from it in having costa semicircular in transverse section (vs. flattened, trapezoid) and sessile gemmae (vs. on long stalks). However, gemmae are rare in G. trichophylla, while in G. muehlenbeckii thay are almost always present.

— Gemmae on branched stalks on ventral side of costa at leaf base — 26
26. Costa flattened dorsally, in transverse section trapezoidal, with two ventral epidermal cells — 9. Grimmia muehlenbeckii

This species is very common in Karelia, rather frequent in Kola Peninsula and Urals and sporadic in lowland European Russia and the Caucasus. Eastwards of the Urals it is known from Taimyr, Yakutia, southern Siberia and Khabarovsk Territory. It grows on shaded acidic rocks (granite, sandstone) in the mountains where it is restricted to the forest regions. It differs from other species of the genus in having small-sized plants, leaves with flattened costae that are trapezoidal in transverse sections and numerous multicellular gemmae on long branched stalks on the ventral side of the costa at the base of its leaves.

— Costa rounded dorsally, reniform in transverse section, with 3–6 ventral epidermal cells — 7. G. lisae

A thermophilous species, known in Russia from one locality on the Black Sea coast in the Western Caucasus. Its distinctive features include arcuate-recurved leaves when wet, thin-walled, non-porose basal juxtacostal cells and reniform costae in transverse section.

27(21). Costa in transverse section reniform with 3–6 ventral epidermal cells — 28
— Costa in transverse section semi-circular or angular with 2 ventral epidermal cells — 34
28. Leaves muticous — 29
— Leaves hyaline hair-pointed — 30
29. Leaves with costae dorsally winged above — 3. G. ramondii

This species is uncommon in Russia and known from a few localities in the NW lowland provinces. It grows on acidic rocks in mesic sites and can be recognized by its large-sized plants and long-lanceolate leaves that have muticous apices and costae with low dorsal wings above.

— Leaves with costae dorsally smooth throughout — 33. G. atrata

A rare species recently found on Kunashir Island (Kurile Islands) near summit of Ruruj Volcano at 1200 m a. s. l. It grows on rocks rich in heavy metals. Its distinctive characters include small, dark-colored plants, and leaves that have muticous apices, strongly sinuose laminal cells and reniform costae in transverse section.

30. Leaf laminae mostly bistratose in upper 2/3; autoicous; setae erect and straight when wet; capsules ovoid-cylindric, smooth — 35. G. longirostris

One of the most widespread mountain species of the genus throughout the world. In Russia it is very common in all mountain areas (except southern Kuril Islands), but absent in the lowlands. It is equally frequent in all altitudinal zones. Grows on acidic and neutral rocks in mesic and dry, shaded and open sites. The species can be recognized in the field by the presence of numerous, cylindrical capsules on long, straight setae, light; straw-colored urns with orange rims; and low-conic opercula with straight or obliquely obtuse beaks. It is quite variable in growth form and in leaf hair-point length, but typically forms small, round cushions or extensive, very hoary mats. Other distinctive features of the species include leaves with partially recurved margins on one or both sides, mostly at mid-leaf, and reniform costae in transverse sections. These features, in combination with its medium-sized plants and partially bistratose upper laminae, allow it to be identified with certainty.

— Leaf laminae mostly unistratose, bistratose in one upper marginal row; autoicous or dioicous; setae arcuate when wet; capsules elliptic, ribbed — 31
31. Plants autoicous, sporophytes frequent; leaf hyaline hair-points densely and sharply spinulose — 4. G. decipiens

This species was recently found in coastal areas of the Black Sea. It can be recognized by its long, densely and sharply spinulose hair-points; laminal cells with moderately thickened sinuose walls; reniform costae in transverse section; and ribbed capsules on arcuate setae.

— Plants dioicous, sporophytes rare; leaf hyaline hair-points moderately dentate — 32
32. Leaves recurved to squarrose when wet; upper leaf cells with moderately thickened walls, sinuose only in mid-leaf; basal juxtacostal cells thin-walled, not porose; Caucasus — 7. G. lisae
— Leaves erect-spreading when wet, upper leaf cells with strongly thickened walls, sinuose in upper 2/3 of leaf; basal juxtacostal cells thick-walled, strongly porose; Asian Russia — 33
33. Costae in transverse sections at mid-leaf and below 3–4-layered; leaf hyaline hair-points straight; Chukotka, rare — 6. G. beringiensis

Only a few collections of this species are known from Chukotka. It grows on calcareous rocks in rocky tundra. Differs from G. jacutica in having leaves with straight hair-points and thicker costae.

— Costae in transverse sections 2-layered throughout; leaf hyaline hair-points often recurved at right angles; East Siberia and Russian Far East, common — 5. Grimmia jacutica

This species occurs in Asian Russia from the Yenisei River basin to Chukotka and Primorsky Territory, but is absent in Kamchatka, Sakhalin and Kuril Islands; it also occurs in Alaska. It is very common in mountain areas in Yakutia. Grows from sea level to the alpine mountain zone (up to 2100 m a. s. l. ) on acidic and neutral rocks, usually in dry sites. G. jacutica is characterised by its odd leaf areolation: longitudinal cell walls very thick and strongly sinuose, sharply contrasting with very thin transverse walls. In this feature it differs from all other species of Grimmia except G. beringiensis, but is similar to Schistidium frigidum and species of Bucklandiella. However, S. frigidum usually has sporophytes and their immersed capsules as well as greatly enlarged perichaetial leaves readily distinguish it from G. jacutica. Bucklandiella differs from G. jacutica in having longitudinal cell walls that are more regularly sinuose, bead-like and less incrassate.

34(27). Plants robust, mainly 3–5 µm high; leaves 2. 5–4. 5 µm long — 35
— Plants medium-sized or small, mainly less than 3 µm high; leaves mostly to 2. 0(–2. 5) µm long — 36
35. Leaf costae furrowed to winged on dorsal side in upper part of leaf, irregularly angular in transverse sections; upper leaf cells papillose, often also bulging; capsules ribbed; setae arcuate when wet — 22. G. elatior

This widespread species is common in the Caucasus and Altai Mts. , rather frequent in Urals, Kola Peninsula and Karelia and sporadic in other areas in Asian Russia (Taimyr, Chukotka, East Sayan Mts. , Transbaikalia and southern Russian Far East). Grows in all altitudinal zones (up to 3100 m a. s. l. ) on dry acidic and neutral rocks in shady and open sites. This species is recognized by its large-sized plants and leaves with long, narrow acumina; papillose and often mammillose upper leaf cells and irregularly angular costae (in transverse section) that strongly projecting dorsally.

— Leaf costae smooth on dorsal side, semi-circular in transverse sections; upper leaf cells not papillose or bulging; [capsules immersed, smooth; setae erect when wet] — 34. G. pilifera
36. Leaf costae weakly winged on dorsal side in upper part of leaf, irregularly angular or trapezoid in transverse sections — 9. G. muehlenbeckii
— Leaf costae smooth throughout on dorsal side, semi-terete or semi-circular in transverse section — 37
37. Leaves lanceolate — 38
— Leaves ovate — 40
38. Leaves narrowly keeled above (blades forming < 40° angle), upper/median leaf cells slightly sinuose; plants autoicous, sporophytes frequent; capsules smooth; setae erect, straight when wet — 26. G. reflexidens

A widespread montane species common in the Caucasus and in the mountains of southern Siberia, sporadic in Kola Peninsula and very rare in North and Subpolar Urals and in Russian Far East. Grows on acidic rocks in alpine zone. Its diagnostic characters include small-sized plants; narrowly keeled leaves; usually partially recurved leaf margins; basal marginal cells with thickened transverse walls; shortly exserted cylindrical capsules on straight seta; smooth light-colored urns; and low-conic mammillate opercula.

— Leaves ±widely keeled above (blades forming > 40° angle); upper/median leaf cells distinctly sinuose; plants dioicous, sporophytes very rare; capsules ribbed; setae arcuate when wet — 39
39. Plants yellowish-green; leaves spirally twisted when dry; leaf cell walls strongly incrassate; in mountain areas throughout Russia — 16. G. funalis

A widespread species, in Russia common in the Kola Peninsula, the Caucasus and Altai Mts. , sporadic in Northern Urals, southern Taimyr, Transbaikalia, Yakutia and Russian Far East (from Chukotka to Primorsky Territory). Grows in all altitudinal zones, but is most frequent above timberline, prefers acidic and neutral rocks. It can be recognized by its spirally twisted leaves (especially on thin, small-leaved shoots) and rather uniform leaf cells with thick, moderately sinuose walls.

— Plants green; leaves slightly flexuose when dry; leaf cell walls moderately thickened; possibly present in westernmost areas of Russia — 8. G. trichophylla
40(37). Leaf hyaline hair-points long and terete, not decurrent; exserted, ribbed capsules usually present; setae long, arcuate when wet — 41
— Leaf hyaline hair-points short to long (sometimes absent in sterile plants), widened and flattened at base, usually decurrent; immersed, smooth capsules occasionally present; setae short, arcuate or erect when wet — 42
41. Perigonia lateral, just below perichaetia; calyptrae mitrate; peristome teeth entire, not or slightly perforate — 12. G. pulvinata

One of the most widespread species of the genus. In Russia it is common in the Caucasus, mainly at low altitudes near sea coasts. It is rather frequent in steppe zone in lowland European Russia and sporadic in the forest zone, where it is known mostly from recent records. Grows on calcareous and, rarely, on acidic rocks and occasionally on artificial substrates (concrete, asphalt, etc. ). It can be recognized by its ovate, unistratose leaves with long hair-points; ribbed capsules on arcuate setae; and lateral perigonia.

— Perigonia terminal; calyptrae cucullate; peristome teeth cribrose — 11. G. orbicularis

This species is very rare in Russia, known only from a few localities in Eastern Caucasus (Dagestan Republic) and from a single site in the lowland part of Krasnodar Territory. Grows on rocks in steppe communities. In habit it is very similar to G. pulvinata, but can be separated by its terminal perigonia, cribrose (vs. subentire) peristome teeth and cucullate (vs. mitrate) calyptrae.

42. Leaves with bistratose strips and patches above — 13. G. anodon
— Leaves unistratose throughout — 43
43. Upper and perichaetial leaves with hyaline hair-points considerably widened and flat­te­ned at base, decurrent — 15. G. capillata
— Upper and perichaetial leaves with hyaline hair-points slightly widened and flattened at base, not decurrent — 14. G. plagiopodia