Arthrorhaphis bullata Frisch & Y.Ohmura, 2022

Frisch, Andreas, Ohmura, Yoshihito, Holien, Håkon & Bendiksby, Mika, 2022, A phylogenetic survey of the ascomycete genus Arthrorhaphis (Arthrorhaphidaceae, Lecanoromycetes) including new species in Arthrorhaphis citrinella sensu lato, TAXON 71 (5), pp. 936-962 : 950-952

Arthrorhaphis bullata Frisch & Y.Ohmura , sp. nov.

– Holotype: JAPAN. Nagano Pref. , Chino-city, Kita Yatsugatake Mts , Kokemomo-no-niwa, 36°03 ′ 29 ″ N, 138°20 ′ 19 ″ E, on mosses on rock, 2100 m, 5 Sep 2014, Ohmura 10976 (TNS barcode TNS-L-126509 !).

Diagnosis. – Arthrorhaphis bullata is characterised within A. citrinella s.l. by esorediate, distinctly convex to bullate-areolate thalli in combination with ascospores (53.0–)72.0– 94.0(–102.0) × (3.5–)3.8–4.5(–5.0) μm in size.

MycoBank 842543

See Fig. 7F for an image of the species.

Description. – Thallus lichenised, forming small irregular colonies over saxicolous bryophytes or plant remains, or a juvenile parasite on unidentified squamulose lichen, up to 2 cm in diam., greenish yellow, areolate; areolae discrete to mostly confluent, irregularly rounded to elliptical to lobate, convex to distinctly bullate, 0.3–1.5 mm, matt to slightly shiny, smooth to verrucose, entire; medulla up to 0.7 mm thick, pale yellow; Ca-oxalate crystals absent. Apothecia lateral or in between the areolae, 0.5–1.1 mm, single or clustered to 2–13, adnate to shortly and broadly stipitate, black, matt, the thick margin first protruding, later level with the flat to distinctly convex, smooth to ± coarsely rugose disc. Epihymenium olive green, HNO 3 green, 12–18 μm. Hymenium unpigmented to pale olive green, densely inspersed, 110–140 μm. Subhymenium up to 250 μm, dirty to brownish olive green. Exciple 70–80 μm wide, dark dirty to brownish olive green, darker towards the outer edge. Paraphyses sparsely branched and anastomosed, 1–1.5 μm wide. Asci 100–130 × 14–17 μm. Ascospores acicular, parallel in the asci, (53.0–)72.0–94.0(–102.0) × (3.5–)3.8–4.5(–5.0) μm (n = 64; l: mean = 83.0, SD = 11.04; w: mean = 4.2, SD = 0.33), (8–)11–14(–16)-septate. Pycnidia not seen.

Chemistry. – Rhizocarpic acid (major), epanorin (minor).

Distribution and ecology. – Arthrorhaphis bullata is known from the mountains of central Honshu and Hokkaido in Japan, and from Primorsky Territory in eastern Russia. The elevation ranges from 915 to 3000 m. Arthrorhaphis bullata typically grows among saxicolous acrocarpous mosses, mostly Andreaea spp. and Grimmiaceae , over a thin soil layer or occasionally directly on soil or rock. The species often occurs in the same localities as A. alpina and A. farinosa , and mixed collections have been seen. Juvenile parasitism on an unidentified squamulose lichen, probably the basal squamules of Cladonia sp. , have been observed in two specimens from Honshu.

Etymology. – The name of the new species refers to the bullate, esorediate areoles that characterise the species within Arthrorhaphis citrinella s.l.

Notes. – Arthrorhaphis bullata is easily distinguished from A. citrinella and A. farinosa by the esorediate, distinctly convex to bullate-areolate thallus. Esorediate specimens of A. vulgaris occurring in Europe and North America may be difficult to separate in the sterile state, but the ascospores are consistently smaller, (34.0–)51.0–72.0(–89.0) × (2.0–)2.2– 3.2(–3.5) μm vs (53.0–)72.0–94.0(–102.0) × (3.5–)3.8–4.5 (–5.0) μm in A. bullata . The Australasian A. catolechioides differs by areolae with a smoother and shinier surface that are either hollow and folded in ridges or rest in umbrella-like fashion on black hyphal strands ( Obermayer, 2001). In the absence of sequence data or well-developed ascospores, A. bullata can be distinguished from A. alpina in eastern Asia with certainty only by the absence of Ca-oxalate crystals in the medulla.

Selected specimens examined (a total of 17 specimens seen). – JAPAN. Honshu. Yamanashi Pref., Kofu-city, Mt Fuji , 35°23 ′ 11 ″ N, 138°42 ′ 20 ″ E, 12 Oct 2012, Ohmura 9439 ( TNS) ; ibid., Minami-Alps-city, Sensui Pass , 35°44 ′ 44 ″ N, 138°14 ′ 02 ″ E, 3 Sep 2012, Frisch 12/ Jp 391 ( TNS) . Nagano Pref., Chino-city, Kita Yatsugatake Mts , 36°03 ′ 29 ″ N, 138° 20 ′ 19 ″ E, 5 Sep 2014, Ohmura 10976 ( TNS) ; ibid., Minamisaku Distr., Kita Yatsugatake Mts , 36°02 ′ 49 ″ N, 138°21 ′ 14 ″ E, 15 Jun 2011, Ohmura 8230 ( TNS) ; ibid., Shimoina Distr., Akaishi Mts, Mt Hijiri , 29 Aug 2001, Inoue 29671 ( TNS) . Fukushima Pref., Minamiaizu Distr., Mt Hiuchi , 7 Oct 2001, Inoue 30223 ( TNS) . Yamagata Pref., Yuza-machi, Mt Chokai , 20–21 Aug 1984, Inoue 16916 ( TNS) . Akita Pref., Sukawako–Mt Magusa–Mt Kurikoma , 22 Aug 1983, Inoue 16735 ( TNS) ; ibid., Moriyoshi-machi, Mt Moriyoshi , 23 Sep 1982, Inoue 22975 ( TNS) . Hokkaido. Kato Distr., Kitaurimaku, Senjokuzure , 5 Jul 2014, Kashiwadani 51466 ( TNS) . RUSSIA. Primorsky Territory, Partizansky Distr. , c. 19 km ESE of Monakino, 43°20 ′ 43 ″ N, 133°39 ′ 26 ″ E, 12 Sep 2014, Ohmura 11643 ( TNS) .

Figures

Fig. 7. A, Arthrorhaphis catolechioides (Moberg & Owe-Larsson NZ2:5, UPS); B, A. citrinella (Odelvik 10598, S); C, A. citrinella (Frisch 15/No100, TRH); D, A. farinosa (Ohmura 9312, TNS); E, A. farinosa (Thor 33718, UPS); F, A. bullata (Ohmura 10730, TNS). — Scale: A, B, E & F, 1 mm; C, 0.5 mm; D, 5 mm. Photos: A. Frisch.