Isopterygiopsis catagonioides (Broth.) Ignatov & Ignatova

Ignatova, E. A., Fedorova, A. V. & Ignatov, M. S., 2020, On the genera Isopterygiopsis and Isopterygiella, gen. nov. (Plagiotheciaceae) in Russia, Arctoa 29 (1), pp. 49-62 : 61

Isopterygiopsis catagonioides (Broth.) Ignatov & Ignatova , comb. nova. —

Orthothecium catagonioides Broth., Nuovo Giorn. Bot. Ital. , n.s. 13: 270. 1906. Figs. 6 , 7C, E, G–H, J–K, N–O , 8.

Stems 1–2(–2.5) cm long, central strand lacking. Leaves appressed, densely arranged, often imbricate, (0.8–)1.0–1.3× 0.4–0.5 mm, ovate, abruptly contracted into filiform, flexuose to reflexed apiculus ca. 0.1 mm long, strongly concave, often cucullate; margins flat, entire; laminal cells 55–90×4–6 µm, alar cells not differentiated. Specialized asexual reproduction by axillary propagulae of 3–4 cells in one row sporadically present. Dioicous. Sporophytes rare. Inner perichaetial leaves 1.3–1.4× 0.3 mm, abruptly contracted into long acumen, margins coarsely dentate above. Setae ca 0.8 cm. Capsules to 1.0 mm long, erect to slightly inclined, straight to slightly curved. Spores 13–17 µm.

Distribution and ecology. This species is sporadically distributed in mountain areas in Asian Russia, from the Arctic to southern Siberia and Far East. In European Russia it is known from Polar Urals. It also apparently occurs in China and North America (see comments to I. muelleriana ; furthermore, one duplicate specimen of this species from Canada is stored in MHA). However, its distribution in these territories needs further study. Isopterygiopsis catagonioides grows in a wide altitudinal range, from sea level (in Iturup Island, Kurils) to 2000 m (in Altai Mts.), in shady cliff crevices and cracks, between rocks of rock-fields, on rock outcrops, in mountain tundra, on cliffs near waterfalls and more or less dry cliffs, in forests and on open slopes, rarely on tree bases, rotten wood and bare soil in forests; it prefers acidic and neutral rocks.

Additional selected specimens examined: EUROPE: RUSSIA: Republic of Komi: Subpolar Urals, Malaya Nyadokota River (tributary of Lemva River ), 21.IV.1950, Kil’dyushevsky s.n. ( LE); Subpolar Urals, Saranseda Creek (upper right tributary of Kozhim River ), 19.IV.1950, Kil’dyushevsky s.n. ( LE) .

ASIA: RUSSIA: Yamalo-Nenetzky Autonomous District: Junto Lake, 14.VIII.1994, Czernyadjeva 16 ( LE); Polar Urals , middle course of Sob’ River , railway station 110 km, 6.VII.1988, Czernyadjeva 7 ( LE). Krasnoyarsk Territory: Taimyr Municipal Distr. : Putorana Plateau, Glubokoe Lake , Fedosov 15-0366 ( MW9046852 ); vicinity of Khatanga Settl., valley of Merkyu River , Fedosov 11-1382 ( MW9046849 ); Anabar Plateau, near Fomich River mouth, Fedosov 08-581 ( MW9045911 ); Maimecha River at 11 km upstream Chopko Creek mouth, Fedosov 09-416 ( MW9045912 ); Kotuikan River at 7 rm upstream Merkyu River mouth, Fedosov 11-1489 ( MW9045916 ). Republic of Buryatia: Barguzinsky Distr. , Barguzinsky Nature reserve , Davsha Settl., Czernyadjeva 64-14 ( MW9112304 ); Kabansk Distr. , Khamar-Daban Range, valley of Bolshoy Mamai Creek , Ignatov, Ignatova & Kolesnikova 18-4014 ( MW9090512 ). Zabaikalsky Territory: Kalar Distr. : vicinity of Kuanda Settl., 4.VIII.2012, Afonina s.n. ( MW9045918 ); vicinity of Udokan Settl., Udokan Range, 28.VII.1985, Filin s.n. ( MW9045919 ). Republic of Yakutia : Oimyakon Distr. , Suntar-Khayata Range, Mus-Khaya Mt. , Ignatov & Ignatova 11- 3250 ( MW9045925 ); Tomponsky Distr. : Suntar-Khayata Range, Kyurbelyakh Creek , Ignatov & Ignatova 11-2233 ( MW9045924 ); Dyby River , Ignatov & Ignatova 17-430 ( MW9090155 ); Momsky Distr. , Ulakhan-Chistai Range, middle course of Tirekhtyakh River , Tas Creek , Ignatov & Ignatova 18-2127 ( MW9091656 ). Khabarovsk Territory: Verkhnebureinsky Distr. : Bureinsky State Reserve , Dusse-Alin Range, Medvezh’e Lake , 5 Ignatov 97-338 ( MW9038116 ); left bank of Bureya River near “Tri Brata”, Ignatov 97-342 ( MW9038115 ); Sovgavansky Distr. : Botchinsky State Reserve , Mulpa River opposite Podzemny Creek mouth, Ignatov & Ignatova 13-167 ( MW9045928 ); Badzhal Mts. , Yarap River valley , Fedosov 16-30 ( MW9112951 ); North Sikhote-Alin , Tardoki-Yani Mt. Range , Sukhaya Pad’ Stream, 28.VIII.2013 Ermolenko 12-8 ( MW9111159 ). Amurskaya Province : Zeya Distr. , Zeisky Nature reserve , Tukuringra Range, Izyubriny Creek , 28. VI.2012, Dudov Br _12_084 ( MW9045931 ); Selemdzhinsky Distr., Norsky Nature Reserve, Meun River , 5.VII.2010, Bezgodov 127 ( MHA9038166 ). Primorsky Territory: Olga Distr. , waterfall on Milogradovka Creek , Ignatov 07-296 ( MW9045930 ); Chuguevka Distr. , Oblachnaya Mt. , Ignatov 07-263 ( MW9045941 ); Partizansk Distr. , Olkhovaya Mt. , Ignatov, Ignatova & Cherdantseva 06- 2672 ( MW9045940 ); Shkotovo Distr. , Pidan (Livadijskaya) Mt. , Ignatov & Ignatova 06-2274 ( MW9045937 ). Sakhalinskaya Province : Sakhalin: Dolinsk Distr. , Sokol, Belaya Creek , Ignatov & Teleganova 06-819 ( MW9045938 ); Tymovsk Distr. , Nabilsky Mt. Range , along a tributary of Khrebtovyj Creek , Ignatov & Teleganova 06-902 ( MW9045939 ); Kuril Islands : Iturup Island : Bogatyr Range, Bakalin K-16-38-07 ( MW9045943 ); vicinity of Circ Bay , 45.32366°N, 148.6187°E, Fedosov 15-2- 216 ( MW9046853 ); Kunashir Island : atrio of Tyatya Volcano , Ignatov 06-1754 ( MW9045936 ). Kamchatsky Territory : Kamchatka Peninsula: Klyuchevskie Volcanoes , Ostryj Tolbachik Volcano , 6.VIII.2006, Czernyadjeva 8 ( MW9045952 ); Kronotskyj State Reserve , Krasheninnikov Volcano , Fedosov 12- 224 ( MW9045953 ); Aleutsky Distr. , Bering Island , Bolshaya Stolovaya Sopka , Fedosov 10-3-1124 ( MW9045955 ) .

NORTH AMERICA: Canada, New Brunswick, Restigouche

Co., 14 Aug 1970 Ireland ( MHA9054883 ) .

Differentiation. Isopterygiopsis catagonioides differs from I. muelleriana in having abruptly vs. gradually narrowed leaf acumina; strongly concave, often cucullate vs. moderately concave, not cucullate leaves; and densely vs. often + sparsely foliate stems. Due to ovate leaves with abruptly attenuate apiculus, I. catagonioides can be confused with widespread Siberian Plagiothecium svalbardense and European Rectithecium piliferum , both having similar leaf shape. However, I. catagonioides differs from both these species in flat leaf margins and presence of stem hyalodermis vs. narrowly recurved margins from base to apiculus and hyalodermis not developed.

Figures

Fig. 6. Isopterygiopsis catagonioides (1, 6-11 – from: Russia, Khabarovsk Territory, Bureinsky Reserve, 14.VIII.1997 Ignatov s.n., MHA; 2-5 – from: Khabarovsk Territory, Tardoki-Yani Mt., Ermolenko 1-17, MHA). 1 – upper laminal cells; 2-3 – capsules; 4, 6, 10 – habit; dry; 5 – peristome; 7-8 – median laminal cells; 9 – gemmae; 11 – stem transverse section; 12 – perichaetial leaf; 13-14 – stem leaves; 15 – basal laminal cells. Scale bars: 5 mm for 4, 6; 2 mm for 2-3, 10; 0.5 mm for 12-14; 200 µm for 5; 100 µm for 1, 7-9, 11, 15.

Fig. 7. Isopterygiopsis muellariana (A–B, D, F, I, L, M) and I. catagonioides (C, E, G–H, J–K, N–O). A–E: habit; F–O: stem transversal cross sections, N–O in addition showing leaves keeled in lower parts. Specimens (specimens from DNA barcoding are cited by isolate ##, cf. Table 1): A, L: Dagestan, OK2497; B: Khabarovsk, OK2411; C, N: Khabarovsk, OK2511; D, F, I: Germany, Tegernsee, 6.I.1919, Herzog, Paul & Schellenberg s.n., MW; E, H, K, O: Urals, Khanty-Mansi, OK2524; G, J, N: Khakassia, OK2507; M: Karachayevo-Circassian Republic, 5.VIII.1999, Ukrainskaya 13913, LE.