Blindiadelphus sibiricus, Fedosov, Vladimir E., Fedorova, Alina V., Ignatova, Elena A. & Ignatov, Michael S., 2017

Fedosov, Vladimir E., Fedorova, Alina V., Ignatova, Elena A. & Ignatov, Michael S., 2017, A revision of the genus Seligeria (Seligeriaceae, Bryophyta) in Russia inferred from molecular data, Phytotaxa 323 (1), pp. 27-50 : 38-42

Blindiadelphus sibiricus Fedosov sp. nov. ( Figs. 3 B–C , 4 B and 5 ).

Type: Russia, Krasnoyarsk Territory, Taimyrsky Municipal Distr., vicinity of Khatanga settl., Kotuy River lower course, Kotuyskoe

Plateau. Left bank of Kotuy River, slope of Chilchikan Mt., 90 m alt., 71º18’41”N; 102º59’32”E, open larch forest, on moist shaded boulder near creek, 22 August 2013, coll. V. Fedosov , # 13-3-1283, Holotype MW!

Diagnosis: Blindiadelphus sibiricus differs from B. diversifolius and B. campylopodus in larger spores, 14–18(–24) μm vs. 8–12 μm, and from B. campylopodus also in straight (vs. cygneous) seta and stem 1.5–10 mm long (vs. ca. 1 mm long). Differences from all other species of Blindiadelphus include broader leaf acumens with rounded apices (vs. narrow, blunt, acute to acuminate). It also differs from B. polaris in smaller plants and capsules not widened at the mouth (usually widened when mature in B. polaris ) and slightly smaller spores (17–26 μm in B. polaris ).

Description: Plants green to dark green or yellowish to brown or blackish when growing in sunny places. Stems 1.5–10 mm long. Leaves spreading when moist, incurved to slightly twisted when dry, 0.7–1.5(–1.8) × 0.3–0.6 mm, from ovate-lanceolate basal portion more or less abruptly narrowed into lanceolate acumen, broadly rounded apex, concave proximally; leaf margin entire or crenulate distally, in 1–2 rows bistratose; costa ends several cells below leaf tip, occupying 1/5–1/3 of the width of acumen, in cross section homogeneous; upper leaf cells rounded-quadrate to short rectangular, 6–9(–11) × 6–8 μm, more or less thick-walled, in basal portion elongate-rectangular, with thick eporose walls, at leaf insertion shorter, alar group weakly to sharply differentiated, subquadrate, inflated. Monoicous, all specimens with sporophytes. Perichaetial leaves slightly enlarged, with elongate, widened to tubulose sheathing base and rather short acumen, obtuse at apex. Setae 2–4.5 mm, straight. Capsules 0.7–1.0 mm, ovate to cylindric, abruptly narrowed to the seta and slightly narrowed to the mouth, pale yellow to brownish. Exothecial cells rectangular or nearly rectangular, thin- to moderately thick-walled. Operculum long rostrate. Peristome teeth dark red, glossy, reflexed outwards and appressed to the capsule wall when dry, trabeculate on outer surface and smooth on inner surface. Spores 14–18 (–24) μm, papillose.

Variation. The species varies greatly both in habit and in several microscopic characters. In two specimens, from Yakutia and Irkutsk Province, plants are much larger than others, with stems up to 1 cm long; they have a conspicuous blackish coloration, unlike green or yellowish-green plants of other specimens. These blackish plants typically have strongly thick-walled cells in basal leaf portion, while in other specimens the basal leaf cells have rather thin to moderately thick walls. A specimen from Yakutia and one specimen from Putorana Plateau differ from other specimens of B. sibiricus in two other respects: (1) they have acuminate rather than rounded leaf tips and (2) spores in both specimens are larger, 20–24 μm in diameter, and papillose, while all other specimens have smooth spores 14–19 μm in diameter. Moreover, the specimen from Yakutia has strongly differentiated, subquadrate and occasionally slightly inflated alar cells, resembling alar cells in Blindia acuta and much more clearly differentiated in comparison with Blindiadelphus polaris and B. subimmersus . Since we revealed only one such unusual specimen, and as it fits B. sibiricus in other morphological characters, as well as in ITS and trn L sequences, we place it in B. sibiricus . Thus, spore size is a key character for species recognition.

Two specimens of B. sibiricus have perichaetial leaves strongly widened at base, thus they were originally placed in B. diversifolius . However, this character appears to be variable within species, including B. diversifolius : some samples resolved in its clade have scarcely widened leaves.

Ecology. Blindiadelphus sibiricus grows in forest and alpine belts on rock outcrops and rock fields on slopes, mostly on somewhat calcareous metamorphic and basic igneous rocks, and also on mineral soil covering rock surfaces.

Distribution. B. sibiricus occurs in Siberia and Russian Far East, from Putorana Plateau and Altai Mts. to Suntar-Khayata Range in Yakutia and northern Sikhote-Alin in Khabarovsk Territory ( Fig. 6). It seems to be not rare on Anabar Plateau and in Czekanovsky Range (Lena River lower course).

Paratypes

Krasnoyarsk Territory: vicinity of Khatanga Settl., Kotuy River middle course, Anabar Plateau , Odikhincha Mt. southern slope, 460 m alt., 70º55’26”N ; 103º00’17”E, brook canyon, on ijolite cliff ledge covered by fine soil near water, 14 August 2011, Fedosov 11-430 (MW).

Other specimens examined

RUSSIA, Altay Republic, Turochak Distr.: Altai Mts, left branch of Kayra Creek near Kayra-Bashi Peak , ca. 1700 m alt., 51º13’N ; 88º02’E, calcareous outcrops on slope near stream, 14 July 1991, Ignatov 13-159 (MHA).

Krasnoyarsk Territory: Taimyrsky Municipal Distr.: vicinity of Noril’sk, Putorana Plateau, southern shore of Glubokoe Lake, NW slope of Sunduk Mt., 470 m alt., 69º16’58”N; 89º54’26”E, brook canyon, on fine soil covering basalt boulder, 15 July 2015, Fedosov 15-0233 (MW); the same place, near snow bed, 14 July 2015, Fedosov 15- 0120 (MW). Zabaikalsky Territory, Kalarsky Distr.: Stanovoe Upland, Kodar Range, Syul’ban River Valley 1370 m alt., 56º50’19”N; 117º18’24”E, S-facing outcrops along Zolotoy Klyuch Brook, on boulder in water, 12 June 2015, Mamontov 528/3 (LE, MW). Republic of Sakha /Yakutia: Bulunsky Distr., Lena River lower course, Chekanovsky Mt. Range, sandstone outcrops along Esesit Creek ca. 20 km upstream its mouth, 33 m alt., 70º46’N; 127º02’E, 7 July 2006, Pisarenko y04/03 (NS, MW); the same area, Tigije Creek 2 km upstream its mouth, 20 m alt., 71º23’N; 127º12’E, sandstone outcrops along creek, 11 July 2006, Pisarenko y08/03, y08/04 (NS, MW); the same area, Kumakh-Surt, 120 m alt., 71º28,392’N; 127º16,08’E, Cassiope tetragona dominated rocky tundra, 12 July 2006, Pisarenko y09/05 (NS, MW); Tomponsky Distr., Verkhoyansky Mountain system, Sette-Daban Range, Segenyakh (Rosomakha) Creek, right bank, 510 m alt., 63º02’N; 137º57’E, rock field at the slope base, on boulder, 16 July 2015, Ignatov & Ignatova 15- 421 (MHA, MW); the same area, Nekyulyakh Creek canyon, 1900 m alt., 63º11’N; 139º29’E, on moist cliffs, 14 July 2003, Ivanova & Zolotov s.n. (MW). Khabarovsk Territory, Nanajsky Distr.: northern Sikhote-Alin, Tardoki-Yani Mt. Range, ca. 4 km northward of Tardoki-Yani Peak, 1880 m alt., 48º54’08.3”N; 137º59’58.8”E, steep E-facing slope in alpine zone, in cliff niche, 25 August 2013, Ermolenko & Bakalin hb-7-16 (MW).

Figures

FIGURE 3. Transverse stem section of Seligeriaceae, showing variation in central strand development. A: Blindia acuta (Caucasus, Ignatov & Ignatova 05-3498, MW), B–C: Blindiadelphus sibiricus (Holotype), D–F: B. recurvatus (Caucasus, Ignatov & Ignatova 05-106, MHA); G–H: Seligeria oelandica (Anabar Plateau, Fedosov 13-3-0812, MW); I: S. trifaria (Caucasus, Lagonaki Plateau, 18 August 1999, Ignatov s.n., MHA) J-M: S. pusilla (Moscow Province, 16 July 1981, Ignatov s.n., MHA). Scale bar 50 μm.

FIGURE 4. Upper exothecial cells of Seligeriaceae. A. Blindiadelphus recurvatus (Caucasus, Ignatov & Ignatova 09-604, MHA); B. B. sibiricus (Holotype), C. B. polaris (Anabar Plateau, Fedosov 13-3-0281, MW), D. Blindia acuta (Caucasus, Ignatova 05-3554, MW), E. Seligeria brevifolia (Kamchatka Peninsula, Kozhin M-263, MW), F. S. pusilla (Caucasus, Ignatov & Ignatova 09-600, MHA), G. S. oelandica (Anabar Plateau, Fedosov 13-3-0812, MW), H. S. tristichoides (Yakutia, Ignatov, 00-544 MW), I. S. donniana (Anabar Plateau, Fedosov 13-3-0717, MW). Scale bar 50 μm.

FIGURE 5. Blindiadelphus sibiricus. A. Habit, wet. B–C. Capsules, without and with operculum. D. Habit, dry. E. Peristome teeth. F. Exothecial cells. G. Upper laminal cells. H. Cells of apical leaf portion. I. Median laminal cells. J–K. Perichaetial leaves. L–N. Cauline leaves. O–P. Basal laminal cells. R. Leaf transverse section. From Holotype. Scale bars: 2 mm for A; 1 mm for B–D; 0.5 mm for J–N; 100 μm for E–I, O–R.