taxonID	type	description	language	source
D57487DCA125E60D5FE1F98C7612F9AA.taxon	distribution	Distribution and ecology. In Russia Didymodon perobtusus occurs in the mountainous areas of southern Siberia. It is most frequent in the East Sayan Mts and is known from several localities in NE surroundings of Baikal Lake, Transbaikalia, Tyva Republic, and Altai Mts. It was also collected on limestone massif Yanganape on eastern slope of Polar Urals. It occurs in altitude range 600 – 2300 m, growing on base-rich rock outcrops on slopes and on river banks, on rocky slopes, on wet cliffs and rocks near waterfalls. Differentiation. Didymodon perobtusus differs from most species of Didymodon by having dark-brown color of plants, ovate leaves with crenulate upper margins, and mostly unicellular axillary gemmae. Its distinction from the similar D. subandreaeoides is discussed under that species. It can be also confused with Bryoerythrophyllum inaequalifolium (Taylor) R. H. Zander, which has similar leaf shape and unicellular gemmae. The latter species differs in having leaves with more strongly recurved margins, densely papillose laminal cells, with c-shaped papillae, and costae with two well-developed stereid bands. Specimens examined: MONGOLIA: Kosogol [Khubsugul] Lake, 27 July 1902 Elenkin (LE) (Syntype). RUSSIA: Yamalo- Nentzky Autonomous District: Eastern slope of Polar Urals, Yanganape limestone massif, Fedosov 17 - 1005, MW 9113061. Altai Republic: Ongudai Distr., Maly Yaloman Creek, 31 July 1991 Ignatov & Ignatova 25 / 170, MHA 9108774; Teletzkoe Lake, Izvestkovaya Mt., 12 July 1989 Ignatov s. n., MHA 9108775. Irkutsk Province: Slyudyanka Distr., Slyudyanka River valley, right bank, Ignatov et al. 18 - 4503, MHA 9027592; same place, left bank, Ignatov et al. 18 - 4620, MHA 9027423. Zabaikalsky Territory: Kalar District, Kodar Range: Valley of Syulban River, left bank of Khadatkan River, 22 June 2015 Afonina 3215, LE B- 0039664; Priargynsky District, Byrka Settl., 30 June 1989 Bardunov s. n., LE B- 0039680. Republic of Buryatia: East Sayan Mts: Okinsky District, East Sayan Mts.: valley of Belyi Irkut River, 12 July 2015 Afonina 1615, LE B- 0039682; Upper of Oka River, Dodo-Zhahna village, 10 km NE of Orlik Settlement, 2 July 2008 Afonina 00708, LE B- 0039691; Upper Oka River, valley of Sorok River, 7 July 2008 Afonina 02208, LE B- 0039673; same place, 10 July 2008, Afonina & Tubanova (Bryophyta Rossica et Civitatum Collimitanearum Exsiccata, Fasc. VIII, № 296), LE B- 0039694; same place, 7 July 2008 Afonina 02108, LE B- 0039688; same place, 10.07.2008 Afonina 03608, LE B- 0039680, LE B- 0039681; Valley of Oka River, Zambbolok Creek, Sailag waterfall, Afonina s. n., LE B- 0039704; Tunkinsky National Park, mouth of Bugovek River (right tributary of Irkut River), Afonina 1222, LE B- 0039699; Tunka Distr., Mondy, 24 Aug 1960 Bardunov s. n., LE B- 0039677; Tunka Range, Khubuta River, 3 Aug 1960 Bardunov s. n., LE B- 0039678.	en	Afonina, M. A., Kuznetsova, O. I., Ignatova, E. A. (2022): A revision of the Didymodon perobtusus group (Pottiaceae, Bryophyta) in Russia. Arctoa 31 (2): 191-204, DOI: 10.15298/arctoa.31.21, URL: https://doi.org/10.15298/arctoa.31.21
D57487DCA125E60D5FE1F98C7612F9AA.taxon	description	H I KFig. 7. Didymodon subandreaeoides (from: Russia, Altai Mts, 15 July 1990, Zolotukhin & Korolyeva s. n., MHA 9108772). A: leaf transverse section; B: upper leaf cells; C – D, F: stem leaves; E: mid-leaf cells; G, J: leaves from innovations; H: habit, dry; I: basal marginal cells of innovation leaf; K: perichaetial leaf; L: basal leaf cells. Scale bars: 2 mm for H; 0.5 mm for C – D, F – G, JK; 100 µm for A – B, E, I, L. mae 17 – 23 µm in diameter, born in clusters in leaf axils. Dioicous, female plants with archegonia occasionally present, male plants not seen. Sporophytes unknown in Russia. [Capsules eperistomate (cf. Inoue et al., 2020)].	en	Afonina, M. A., Kuznetsova, O. I., Ignatova, E. A. (2022): A revision of the Didymodon perobtusus group (Pottiaceae, Bryophyta) in Russia. Arctoa 31 (2): 191-204, DOI: 10.15298/arctoa.31.21, URL: https://doi.org/10.15298/arctoa.31.21
D57487DCA125E60D5FE1F98C7612F9AA.taxon	distribution	Distribution and ecology. Like Didymodon perobtusus, D. subandreaoides occurs in Russia in southern Siberia from Altai to Buryatia and Transbaikalia; it was also found in several localities in Yakutia: Sette Daban, Suntar-Khayata and Ulakhan-Chistai Mt. Ranges, and in Beringian Chukotka. It is also known from single locality in Tokinsky Stanovik Range (Amur Province). The species grows at low altitudes in Chukotka and Yakutia, 50 – 1000 m a. s. l., while in the mountains of southern Siberia it was found between 1200 and 1700 m. It occurs in arctic and mountain tundra of forb-sedge type, on rock outcrops in moss-lichen community, on boulders in larch forest, on rocky banks of creeks and rivers, on wet limestone cliffs near waterfalls and in places with dripping water (melting permafrost), in Yakutia occasionally in places where Andreaeobryum macrosporum Steere & B. M. Murray was collected. Differentiation. Didymodon subandreaeoides is very similar to D. perobtusus in plant color, leaf shape, crenulate upper leaf margins, and thick-walled, papillose laminal cells; it even possesses unicellular axillary gemmae in some populations. However, the presence of innovations with small, strongly concave leaves is a unique feature of D. subandreaeoides. It also separates this species from similar species of Didymodon and other genera of the Pottiaceae. Specimens examined: RUSSIA: Chukotka: Lavrentiy Bay, Krauze Cape, 2 Sept 1975. Afonina s. n., LE B- 0039663; Chegitun’ River basin, 24 July 1972 Razzhivin s. n., LE B- 0039662; same place, 1 km upstream from Putukuneiveem River mouth, 24 July 2003, Razzhivin s. n., LE B- 0039661. Republic of Sakha / Yakutia: Momsky Distr., Ulakhan-Chistai Mt. Range, western foothill of Mramornaya Mt., Ignatov & Ignatova 18 - 1360, MW 9091288; same place, 930 m alt., Ignatov & Ignatova 18 - 1815, MHA 9029531; Pravy Dzhapkychan Creek, Ignatov & Ignatova 18 - 2712, MHA 9028794; Tomponsky Distr.: left bank of Vostochnaya Khandyga River opposite Segenyakh Creek moutyh, Ivanov 17 - 729, MHA 9027663; Sette Daban Range, right slope of Vostochnaya Khandyga River valley between Shaman and Segenyakh Creeks, Ignatov & Ignatova 16 - 1563, MHA 9021499; same place, Shaman Creek, Ignatov & Ignatova 17 - 32, MHA 90256925. Republic of Buryatia: Okinsky J K O District, East Sayan Mts.: upper of Oka River, Valley of Sorok River, alt. 1755 m, 9 July 2008 Afonina 03008, LE B- 0039657; Okinsky District, East Sayan Mts, Valley of Belyi Irkut River, 12 July 2015 Afonina 1715, LE B- 0039656; Kurumkan District, Dzherginskiy State Reserve. Upper Barguzin River, 1 Aug 2013 Mamontov YuSM- 386 - 1, LE B- 0039659 & LE B- 0039660; NE Baikal, Tompuda River, 19 Aug 1956 Bardunov s. n., LE B- 0039658; East Sayan Mts, Kadyr-Os River near Chuglyma Creek mouth, 13 July 1961, Bardunov s. n., MHA 9108778. Z ABAIKALSKY TERRITORY: Kalar District, Kodar Range: Levyi Syulban River, 10 June 2015 Afonina 0715, LE B- 0039665; Syulban River, Zolotoi Klyuch Creek, 12 July 2015 Afonina 0915 / 1, 0915 / 2 & 0915 / 3, LE B- 0039666, LE B- 0039669, LE B- 0039670; same place, 13 June 2015 Afonina 1515, LE B- 0039667; Kalar District, Kodar Range: Valley of Syulban River, left bank of Khadatkan River, 22 June 2015 Afonina 3215, LE B- 0039668; valley of Syulban River, upper of Oleniy Rog Creek, 16.06.2015 Mamontov 536 / 2 b, LE B- 0039671; AMUR PROVINCE: Zeya Distr., Stanovoy Ridge, Tokinsky-Stanovoy National Park, vicinity of the Tas-Balagan pass, Dudov TSMF 005, MW 9092493.	en	Afonina, M. A., Kuznetsova, O. I., Ignatova, E. A. (2022): A revision of the Didymodon perobtusus group (Pottiaceae, Bryophyta) in Russia. Arctoa 31 (2): 191-204, DOI: 10.15298/arctoa.31.21, URL: https://doi.org/10.15298/arctoa.31.21
D57487DCA12CE60D5FBFF9E577BFFA4D.taxon	biology_ecology	Ecology. The species was collected on one locality on Sakhalin Island, at the top of low calcareous ridge, in crevices and on surfaces of dry cliffs. Specimens examined: RUSSIA: Sakhalinskaya Province, Sakhalin Island, Smirnykh Distr., Nature Reserve “ Vaida Mountain ”, 900 m alt., Ignatov & Teleganova 06 - 3543, MW 9036033; same place, 920 m alt., Ignatov & Teleganova 06 - 3544, MW 9036034.	en	Afonina, M. A., Kuznetsova, O. I., Ignatova, E. A. (2022): A revision of the Didymodon perobtusus group (Pottiaceae, Bryophyta) in Russia. Arctoa 31 (2): 191-204, DOI: 10.15298/arctoa.31.21, URL: https://doi.org/10.15298/arctoa.31.21
