Sphagnum mirum Flatberg & Thingsgaard, Bryologist

Flatberg, Kjell I., Afonina, Olga M., Mamontov, Yuriy S., Fedosov, Vladimir E. & Ignatova, Elena A., 2016, On Sphagnum mirum (subgen. Squarrosa) and S. olafii (subgen. Acutifolia), Arctoa 25 (1), pp. 96-101 : 96-101

Sphagnum mirum Flatberg & Thingsgaard, Bryologist 106: 504. f. 1, 3–21, 26–29. 2003[2004]. Fig. 1

Plants medium-sized, yellowish-brown, forming low hummocks. Stems yellowish-green, with 2–3 layered

1 – University Museum, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; e-mail: [e-mail]

2 – V. L. Komarov Botanical Institute Rus. Acad. Sci., Prof. Popov Str., 2, St. Petersburg, 197376 Russia – Россия 197376, г. Санкт-Петербург, ул. проф. Попова , д. 2, Ботанический институт им . В.Л. Комарова РАН; e-mail: [e-mail] and [e-mail]

3 – Tsitsin Main Botanical Garden, Russian Academy of Sciences, Botanicheskaya 4, Moscow 127276 Russia – Россия 127276 Москва, Ботаническая 4, ГБС РАН; e-mail: [e-mail]

4 – Moscow State University, Faculty of biology, Vorob’ovy gory 1-12, Moscow 119991 Russia – Россия 119234, Москва, Московский университет, Биологический факультет, каф. геоботаники; e-mails: [e-mail] and [e-mail] hyalodermis. Stem leaves 1.45–1.7× 0.8 mm, lingulate, with narrow, poorly defined border, broad fimbriate apex and non-septate hyaline cells without pores and fibrils. Branch fascicles of 2 spreading and 1–2 hanging branches. Branch leaves 1.4–1.75 mm long, ovate, with a narrow involute tips; hyaline cells in proximal half of leaf aporose on convex surface and with large elliptic pores on concave surface; hyaline cells on convex surface in distal half of leaf with numerous rather large pores at cell ends and along comissures, on concave surface with large round pores; chlorophyllous cells in transverse section of branch leaf narrow elliptical, enclosed on both surfaces, with the widest part in the leaf middle. Gametangia and sporophytes not seen in Russian collections. [Sexual condition dioicous. Spores ca. 31 µm].

Differentiation. S. mirum is closely related to S. teres (Schimp.) Ĺngstr. and S. tundrae Flatberg. According to Flatberg & Thingsgaard (2003), the most prominent morphological characters of S. mirum are chlorophyllous cells in transverse section elliptical to elliptical-rectangular, broadest in middle part, broadly enclosed on both surfaces vs. triangular to ovate-triangular, broadest near convex surface ( S. teres ) and elliptic to elliptic-ovate, broadest at some distance apart from the convex surface ( S. tundrae ); distinctly papillose inner surface of hyaline cells where facing chlorophyllous cells vs. less distinctly papillose in both S. teres and S. tundrae ; pendent branch leaves markedly shorter than divergent branch leaves vs. not markedly shorter ones in both S. teres and S. tundrae . The main difference between S. mirum and S. teres includes opposide position of pores in hyaline cells in proximal part of branch leaves: S. mirum has aporose hyaline cells on convex surface and large faint pores on concave side, while in S. teres pores are present on convex side and absent on concave one. In S. tundrae , pores are present in hyaline cells on both surfaces of basal part of branch leaves. In addition, S. mirum can be separated from S. tundrae by narrow involute tips of branch leaves, which are broadly truncate in the latter species.

Distribution. Sphagnum mirum was recently described from Alaska ( Flatberg & Thingsgaard 2003) based on material collected from one locality in the Bethel area. In 2007 it was collected by the first author from one locality in the Nunavik area, arctic Canada (62°22’57’’N – 77°52’15.9’’W; TRH B-727552-54). Specimens from Russia were reffered to S. mirum by Flatberg in 2011, but remained unpublished. The species was also reported from Yakutia ( Ignatova et al., 2011; Ignatov et al., 2014), but these specimens were reidentified later as S. tundrae .

Ecology. In Taimyr the species occurs in boggy cotton-grass ( Eriophorum vaginatum , E. polystachion ) dominated tundra, with Betula exilis, Salix hastata, S. reptans, Carex concolor, Pedicularis spp., Tomentypnum nitens, Dicranum elongatum, Aulacomnium palustre, Scorpidium revolvens, Hamatocaulis vernicosus, Calliergon giganteum, Sphagnum beringiense , S. tundrae , etc. It was collected on hummock near a small lake. For more details about the area and its bryophyte flora see Norin (1978) and Fedosov & Afonina (2009). In Zabaikalsky Territory S. mirum grew in dwarf birch dominated community with peat mosses and swampy willow stand, at 1140 m a.s.l.

Specimens examined: Krasnoyarsk Territory: Taimyr Municipal District, Khatanga Settlement outskirts, Ary-Mas key area, on the left bank of Novaja River near Ary-Mas Station of Taimyrsky State Reserve (72°28’N – 110°52’E), 1.IX.2007, Fedosov 07A-1-3, 07A-1-10, det. Flatberg ( MW). Zabaikalsky Territory: Kalar District , Baikal-Amur Mainline, Nalednaya crossing point (56°30’22”N – 117 °07’29”E), 1140 m alt., 6.VIII.2012, Afonina 7712 & 7612 ( LE) .

Sphagnum olafii Flatberg , Journal of Bryology 17:

613. f. 1–4. 1993. Fig. 2

Plants medium-sized, in soft and compact tufts, brownish or lightly pinkish, capitulum fattened. Stem green-brownish; hyalodermis 2–3-layered, cells of outer layer aporose or with one (rarely two) semicircular pores in cell ends, without fibrils. Stems leaves lingulate-triangular, often with somewhat involute margins above; apex subacute, obtuse, often narrowly truncate; 1.4– 1.7×0.75–08 mm; hyaline cells on convex surface faintly fibrillose, septate, without pores. Branch fascicles with 2 spreading and 1 (rarely 2) pendent branches. Branch leaves ovate-lanceolate, 1.6–2.0 mm long; hyaline cells on convex surface in middle part of leaf with elliptic commissural pores, on concave surface with large circular pores; chlorophyllose cells in transverse section triangular to sometimes triangular-trapezoidal, exposed to both surfaces or sometimes distinctly enclosed on convex surface. Sexual condition autoicous. Spores 24–30 µm.

Flatberg (2007) reported S.olafii with sporophytes from western Greenland, and in 2009 sporophyte-bearing plants of the species were collected in northeast Greenland in the Zackenberg Area, the photo of this species made by K Hassel is provided in his publication ( Hassel et al., 2014). Sporophytes also present in one of collections from Chukotka (Egvekinot Settlement surroundings). The capsule is mature, but with intact operculum and with short pseudopodium ( Fig. 2 : 1). It could remain not open due to unfavorable weather condition.

Differentiation. Sphagnum olafii is similar to S. arcticum Flatberg , and the specimens from Chukotka Peninsula were initially identified by R. Gauthier as S. arcticum (Afonina, 2004) . Flatberg (1993, 2007) mentioned that both stem and branch leaves of S. olafii are longer and narrower than leaves of S. arcticum ; however, in some Russian specimens of the former species leaves are slightly shorter than they are originally described, and are comparable in length to leaves of S. arcticum (see Fig. 3 : 1– 12, specimens also from Russia). At the same type, shape of stem leaves is different in these species: in S. olafii they are more acute, considerably narrowed to the apex, but broadly truncate and lacerate above, whereas in S. arcticum they are broadly lingulate or even lingulatespathulate, not narrowed distally, with broadly obtuse and more or less fimbriate-lacerate apex. Narrowed, but truncate apex of stem leaves is a distinctive character of S. olafii , separating it from some other species of sect. Acutifolia with similarly acute stem leaves, like S. capillifoli-

1 2 3 7 8 9

4 5

10 11 12

1 mm

13 14 15

16 17

um and S. subnitens , which are not truncate or lacerate at apex. Absence of metallic lustre is helpful for distinguishing S. olafii from S. subfulvum .

Distribution. The species was described by K.I. Flatberg (1993) from Svalbard and consequently was found in Greenland and North America ( Canada, Quebec) ( Flatberg, 2007; Hassel et al., 2014). The finding in Zabaikalsky Territory is the first southernmost locality and first time record for Russia.

Ecology. In Zabaikalsky Territory the species was collected in tundra belt (1780 m alt.). In Chukotka the habitats of S. olafii are confined to the wet dwarf-willow and dwarf-birch-sedge-mossy tundras on upland terrace and on gentle slope. The moss cover in these tundras is formed by such species as Aulacomnium palustre , Hylocomium splendens, Oncophorus wahlenbergii, Racomitrium lanuginosum, Tomentypnum nitens, Scorpidium revolvens, Warnstorfia sarmentosa, etc.

Specimens examined: Russia: Southern Siberia, Zabaikalsky Territory: Kalar District, Kodar Range, upper of Sredny Sakukan River , Medvezhy Brook (56°54’35.4”N – 117°36’44.7”E), 1780 m alt., tundra belt, on stones in dry brook bed, 1.VII.2013, Mamontov 338/1 ( LE, TRH) . Chukotka Autonomous Okrug: Middle course Getlyanen River (65°10’N – 173°00’W), sedge-sphagnous bog, 5.VIII.1976, Afonina s.n. ( LE, TRH) ; Bay Cross, vicinity of Egvekinot Settlement (66°20’N – 179°07’W), hummocky dwarf-willowsedge-mossy tundra in lower part of slope, 17.VIII.1977, Afonina s.n. ( LE, TRH) ; vicinity of Ioni Lake, Ioni Mt in middle course of Ioniveem Creek (65°53’N – 173°44’W), in hummocky dwarf birch-blueberry-sedge-mossy tundra with wet depressions, 5.VII.1977, Afonina s.n. ( LE, TRH) .

Figures

Fig. 1. Sphagnum mirum Flatberg & Thingsgaard (1–2, 4, 6–12 from: Russia, Taimyr, Fedosov 07A-1-10, MW; 3, 5 – from: Russia, Zabaikalsky Territory, Afonina 7712, LE). 1 – part of stem and branch fascicle, dry; 2 – branch leaf transverse section; 3–4 – branch leaves; 5–6 – stem leaves; 7 – cells on convex surface of branch leaf in its middle part; 8 – cells on concave surface of branch leaf in its middle part; 9 – cells on convex surface of stem leaf in its distal part; 10 – stem transverse section; 11 – cells on convex surface of branch leaf at its base; 12 – cells on convex surface of branch leaf at its base. Scale bars: 5 mm for 1; 1 mm for 3-6; 100 µm for 2, 7–12.

Fig. 2. Sphagnum olafii Flatberg (from: Russia, Chukotka, 17.VIII.1977 Afonina s.n., LE). 1 – part of plant with capitula and sporophyte, dry; 2 – part of stem and branch fascicle, dry; 3 – branch leaf transverse section; 4 – hyalodermis; 5 – stem transverse section; 6–8 – stem leaves; 9–11 – branch leaves; 12 – cells on convex surface of stem leaf in its distal part; 13 – cells on convex surface of branch leaf in its middle part; 14 – cells on concave surface of branch leaf in its middle part. Scale bars: 5 mm for 1–2; 1 mm for 6-11; 100 µm for 3–5, 12-14.

Fig. 3. Stem and branch leaves of Sphagnum olafii Flatberg, S. arcticum Flatberg & Frisvoll and S. mirum Flatberg & Thingsgaard. 1–6 – S. olafii (from: Russia, Chukotka, 17.VIII.1977 Afonina s.n.,2 LE). 7–12 – S. arcticum (7–8, 10–11 from: Zabaikalsky Territory, 25.VII.1975, Garashchenko 07, LE; 9, 12 – from: Taimyr, Fedosov 05-178, MW). 13–20 – S. mirum (13–16 from:Taimyr,Fedosov 07A-1-10, MW; 17–20 from: Zabaikalsky Territory, Afonina 7712, LE). 1–3, 7–9, 13–14, 17–18 – stem leaves; 4–6, 10– 12, 15–16, 19–20 – branch leaves. Scale bar: 1 mm for all.