Micarea osloensis (Th. Fr.) Hedl.

Kantelinen, Annina, Svensson, Måns, Malíček, Jiří, Vondrák, Jan, Thor, Göran, Palice, Zdeněk, Svoboda, Stanislav & Myllys, Leena, 2024, A phylogenetic study of Micarea melaeniza and similar-looking species (Pilocarpaceae) unveils hidden diversity and clarifies species boundaries and reproduction modes, MycoKeys 106, pp. 327-353 : 327-353

Micarea osloensis (Th. Fr.) Hedl.

Fig. 4 A, E

Type.

Bih. Kongl. Svenska Vetensk. Akad. Hand. III, 18: 97 (1892). Lecidea osloensis Th. Fr. Lich. Scand. 2: 524 (1874). Type: Norway, Oslo, In cacumine Ryenbjerget, 10 July 1874. N. G. Moe (UPS L- 153276! – holotype).

Description.

Thallus endoxylic or visible as a thin pale greenish-grey to dark green-grey layer on top of substrate. Photobiont micareoid, 4–7 µm in diam.

Apothecia infrequent or rare, absent or numerous, immarginate, convex to hemispherical, dark brown to black, matt, simple, 0.1–0.2 (– 0.3) mm in diam. Hymenium 30–50 µm tall (Coppins c. 30 µm tall), hyaline, sometimes olivaceaous, often with warm brown vertical streaks, K –, HNO 3 – (Superba-brown). Epihymenium warm dark brown to blackish (Coppins: red-brown), rarely greenish, mostly K – but sometimes K + green, HNO 3 – or HNO 3 + purplish (Cinereorufa-green). Paraphyses of two type: 1.) hyaline or coated with a brown pigment, thick, 2–3 µm wide, simple or branched, sometimes wider from apices, often uneven in shape, abundant, sometimes concentrated into fascicles, 2.) thinner, c. 1–1.5 µm wide, rarely branched, rare. Asci cylindrical to cylindrical-clavate, 30–40 × 10–12 µm (Coppins: 26–30 × 11–13 µm). Ascospores 7–10 × (2.5 –) 3.0–3.5 (– 4.0) µm (Coppins: 6–9.5 × 3–4 µm), ellipsoid, cylindrical or sometimes roughly shaped, 0 (– 1) sept. Hypothecium warm dark brown (Coppins: red-brown), composed of hyaline hyphae 1–2 µm wide surrounded by brown pigment giving it an unevenly coloured / randomly spotted appearance, K –, HNO 3 – (Superba-brown), c. 85 µm tall.

Mesopycnidia often numerous and crowded, sometimes absent, simple or branched from the base, emergent or shortly stalked ca. 50–180 µm tall, 40–70 µm in diam., dark brown to blackish, walls brown, greenish brown from the top with a warm brown lower part, K – (Superba-brown) or sometimes K + green, HNO 3 – or HNO 3 + purplish (Cinereorufa-green), usually extruding white mass of conidia that may merge with neighbouring conidia. Mesoconidia ellipsoid or short cylindrical 3.5–4.5 (– 5) × 1.2–1.5 (– 1.8) µm. Micro- or macropycnidia not seen.

Chemistry no substances detected by TLC ( Coppins 1983).

Crystalline granules not present in apothecia, pycnidia or thallus.

Habitat and distribution.

The type of M. osloensis occurs on soil. Another morphologically identical specimen collected in 2007 occurs on bark of decaying trunk (Palice 11684). Our newer specimens occur on bark, dead wood and dead mosses. The type specimen was collected from Norway from a woodland clearing on the site of an old bonfire, and the newer specimens are from the Czech Republic, Finland, Sweden and Ukraine. In the Czech Republic, M. osloensis occurs commonly from middle to montane elevations. It appears to be toxitolerant and is known in areas with higher levels of air pollution in the past (i. e. acidification by acid rain). The typical habitats are bark on bases and roots of Fagus sylvatica , Larix decidua , Picea abies , Pinus sylvestris . It is abundant also on dead wood and dead bark on stumps, fallen trunks and snags. In Finland, M. osloensis is likely relatively common but overlooked in coniferous forests on bark, dead wood and dead mosses. In both countries, M. osloensis is known from managed and old-growth forests.

Notes.

The two previously known M. osloensis specimens, including the type, have not been sequenced, although an unsuccessful sequencing attempt of a specimen collected by Palice (11684) was made by Kantelinen in 2011, and therefore we cannot compare our new specimens to the type of M. osloensis using DNA. Subtle morphological features differentiate the type from new specimens, i. e. taller hymenium and asci. Most of the new specimens are K – and have only the Superba-brown pigment, similar to the type. However, some specimens have a K + greenish, HNO 3 + purple reaction in the epihymenium and pycnidial walls suggesting the presence of the Cinereorufa-green pigment which is not known from the type of M. osloensis . Specimens with the Cinereorufa-green pigmentation appear to be more frequent in the Czech Republic. The Finnish specimens have sometimes olivaceous tones that are K – but slightly HNO 3 + purple.

Another difference between the type of M. osloensis and our newly sequenced specimens is reproduction. The type specimen has apothecia and no pycnidia. The new specimens, on the other hand, often have shortly stipitate pycnidia. Our specimens appear to be dimorphic, however, so that the specimens represent either sexual (rare) or asexual reproduction modes which are monophyletic in DNA level.

Because of overlapping variation in reproduction and pigmentation between the type of M. osloensis and our new specimens, we cannot exclude the possibility that they are conspecific. On the other hand, we also cannot exclude the possibility that the new specimens represent a yet undescribed taxon in the M. melaeniza group.

M. osloensis resembles M. eurasiatica , M. melaeniza , M. misella and M. nigella . The most important characters of M. osloensis are the combination of sessile to shortly stalked pycnidia, mesoconidia of the size 3.5–4.5 (– 5) × 1.2–1.5 (– 1.8) µm, warm-brown, sometimes olivaceous colouration in apothecia and pycnidia (Coppins: red-brown), and often a K – reaction. Micarea eurasiatica sp. nov. has mostly sessile to emergent pycnidia and bigger mesoconidia (( 4 –) 4.5–6.0 × 1.2–1.5 (– 1.8) µm). Micarea misella , on the other hand, has a K + violet reaction in the epihymenium and pycnidia ( Coppins 1983; Czarnota 2007). Micarea nigella has similar mesoconidia and spore size, but its pycnidia are usually taller and it has the brown / purple-brown Melaena-red pigment (K + green) in hypothecium and pycnidia.

Based on our phylogenetic analyses, M. osloensis and M. melaeniza are sister species. They have morphological similarities including pigmentation and spore size. However, M. osloensis has slightly larger mesoconidia, shorter pycnidia and wider often roughly shaped paraphyses. The concentration of the Cinereorufa-green pigment (K + green, HNO 3 + purple) appears to vary in both taxa, but especially in M. osloensis . Micarea melaeniza is mostly K + green in epihymenium, hymenium, upper hypothecium and pycnidia. Micarea osloensis , on the other hand, is rarely K + green and then from the epihymenium and pycnidia.

Additional specimens studied.

Czech Republic, Northern Bohemia, Jizerské hory Mts, Josefův Důl: valley of Jedlový potok, protected zone of nature reserve Jedlový důl, fragment of fir-beech old-growth forest, 50 ° 47 ' 45 " N, 15 ° 14 ' 47.5 " E, on dry wood of old conifer stump, 780 m, 2020, Palice 30266, PRA (in GenBank as M. nigella : OQ 646320); ibid., Hejnice, Jizerskohorské bučiny National Nature Reserve, valley of Velký Štolpich brook, S of Ořešník Mt. (800 m), ca 50 ° 51 ' 13 " N, 15 ° 11 ' 13 " E, 660 m, on base of Fagus sylvatica , 2013, Malíček 6020, hb Malíček. Lužické hory Protected Landscape Area, Mařenice, Horní Světlá: managed spruce-beech forest on E-facing slope, 0.3 km NNW of Kopřivnice Hill (638 m), 50 ° 50 ' 13.6 " N, 14 ° 37 ' 56.6 " E, 600 m, at base of Picea abies , on stump of Picea , 2020, Malíček 14019, 14020 & Rydlo, hb Malíček. Central Bohemia, Brdy Protected Landscape Area, Míšov, Na Skalách Nature Reserve, old-growth beech forest, small scree with rock outcrops and sparse spruce forest in NW part of the protected area, 49 ° 36 ' 20 " N, 13 ° 45 ' 56 " E, 715–740 m, at base of Fagus sylvatica , 2023, Malíček 16281, hb Malíček. Brdy Hills, Rožmitál pod Třemšínem, Nepomuk: managed forest 0.4 km N of Praha Hill (862 m), 49 ° 39 ' 48 " N, 13 ° 49 ' 06 " E, 825 m, at base of Larix decidua , 2018, Malíček 12007 & Vondrák, hb Malíček; ibid., Strašice, managed mixed forest 3 km E of village, 49 ° 43 ' 34 " N, 13 ° 47 ' 56 " E, 610 m, at base of Larix decidua , 2018, Malíček 12000 & Vondrák, hb. Malíček. Příbram, Brdy Hills, Jince managed coniferous forest 0.5 km SSE of Velcí pond, 49 ° 45 ' 17 " N, 13 ° 56 ' 34 " E, 600 m, at base of Larix decidua , 2018, Malíček 12016 & Vondrák, hb Malíček. Eastern Bohemia, Rychnov n. Kněžnou, Orlické hory Protect. Lands. Area, Rokytnice v Orlických horách, Černý důl Nature Reserve, fragment of old-growth beech-spruce-silver fir forest, along brook, 50 ° 12 ' 01.4 " N, 16 ° 31 ' 18.2 " E, 800–810 m, on bark of stump of Picea abies , 2012, Malíček 4536 et al., hb Malíček. Žďár nad Sázavou, Žďárské vrchy Protected Landscape Area, Svratka fragment of old beech predominated forest 0.6 km SW of Spálený kopec Hill (766 m), 49 ° 43 ' 18.2 " N, 16 ° 06 ' 11.4 " E, 750 m, on stump of Picea abies , 2020, Malíček 13864 & Sejfová, hb Malíček; ibid., Svratka, Pustá Rybná: spruce-beech forest on S-facing slope of Kaštánkův kopec (753 m), 49 ° 43 ' 03.9 " N, 16 ° 06 ' 46.4 " E, 740 m, on stump of Picea abies , 2020, Malíček 13953, hb Malíček. Svitavy, Česká Třebová managed spruce forest 3 km W of Opatov, 49 ° 49 ' 47.6 " N, 16 ° 27 ' 40.0 " E, 445 m, on stump of Picea abies , 2020, Malíček 13970 & Šámalová, hb Malíček. Western Bohemia, Český les Protected Landscape Area, Tachov, Lesná: young beech forest 0.8 km E of Knížecí strom Hill (829 m), 49 ° 45 ' 54.2 " N, 12 ° 29 ' 18.5 " E, 780 m, on stump of Picea abies , 2020, Malíček 13784 & Rydlo, hb Malíček; ibid., spruce-beech forest 1 km NE of Knížecí strom Hill (829 m), 49 ° 46 ' 17.3 " N, 12 ° 29 ' 18.1 " E, 770 m., at base of Picea abies , 2019, Malíček 13167 & Rydlo, hb Malíček; ibid., Pec, Bystřice Nature Reserve, natural mixed forest up to 150 years old, 49 ° 22 ' 56 " N, 12 ° 48 ' 39 " E, 650 m, at base of Picea abies , 2015, Malíček 8028, hb Malíček. Kdyně, Mezholesy: managed mixed forest 0.3 km SE of Koráb Hill (773 m), 49 ° 23 ' 37.7 " N, 13 ° 04 ' 44.1 " E, 750 m, at base of Picea abies , 2019, Malíček 13371 & Rydlo, hb Malíček. Southern Bohemia, Novohradské hory Mts, Horní Stropnice, NPP Hojná Voda, fragment of primeval forest predominated by beech, 48 ° 42 ' 20 " N, 14 ° 45 ' 08 " E, 840–870 m, on snag, 15 October 2019, Malíček 13500, herb. Malíček. Šumava Mts., Volary, Nová Pec, 740 m, 48 ° 49 ' 11.2 " N, 13 ° 56 ' 12.151 " E, on bark of Pinus sylvestris at base of trunk, 2017, Vondrák 19007, PRA. Prachatice, Šumava Protected Landscape Area, Kubova Huť, Boubínský prales National Nature Reserve, managed spruce forest c. 120 years old, 0.4 km NNE of top of Mt Boubín (1362 m), 48 ° 59 ' 42.2 " N, 13 ° 49 ' 05.7 " E, 1275 m, on decaying stump 2015, Malíček 8349 & Palice, hb Malíček. Jindřichův Hradec, Javořická vrchovina Hills, Stráž nad Nežárkou, Sedlo: managed coniferous forest SSE of Otínský kopec Hill (538 m), 49 ° 02 ' 44.0 " N, 14 ° 59 ' 45.7 " E, 530 m, on stump, 2020, Malíček 13817, hb Malíček; ibid., Lásenice: mixed forest S of Šemburský rybník, 49 ° 03 ' 34.6 " N, 14 ° 59 ' 55.2 " E, 520 m, on stump, 2020, Malíček 13821, hb. Malíček; ibid., managed coniferous forest between Nová Ves and Sedlo, 49 ° 03 ' 36.1 " N, 15 ° 00 ' 55.3 " E, 560 m, at base of Pinus sylvestris , 2020, Malíček 13824, hb Malíček. Tábor Chýnov, young beech forest SSE of Blanička, 49 ° 28 ' 00.6 " N, 14 ° 50 ' 34.9 " E, 690 m, on fallen wood, 2020, Malíček 13834 & Rydlo, hb Malíček; ibid., mixed forest SE of Batkovy Hill (724 m), 49 ° 27 ' 43.3 " N, 14 ° 50 ' 00.9 " E, 700 m, at base of Larix decidua , 2020, Malíček 13838 & Rydlo, hb Malíček. Northern Moravia, Jeseník, Jeseníky Protected Landscape Area, Bělá pod Pradědem, Vysoký vodopád, Nature Reserve, valley of Studený p. brook, ca. 50 ° 06 ' 57 " N, 17 ° 12 ' 10 " E, 900–1000 m, on base of Picea abies , 2012, Malíček 5102, hb Malíček. Šumperk, Králický Sněžník Mts, Staré Město: Mt. Králický Sněžník, c. 100 years old spruce forest on S-facing slope 0.1 km SE of Františkova chata, 50 ° 12 ' 05.2 " N, 16 ° 51 ' 28.3 " E, 1210 m, at base of Picea abies , 2015, Malíček 8381, Kocourková & Vondrák, hb Malíček. Eastern Moravia, Beskydy Protected Landscape Area, Bílá, Salajka: beech dominated forest 0.6 km SE of gamekeeper’s house, 49 ° 24 ' 37.9 " N, 18 ° 25 ' 39.5 " E, 730 m, on decaying stump, 2019, Malíček 13344 & Rydlo, hb Malíček; ibid., Frenštát pod Radhoštěm, Kněhyně-Čertův mlýn National Nature Reserve, W-facing slope of Kněhyně Mt. (1257 m), old-growth spruce forest above red-marked tourist path, 49 ° 29 ' 57 " N, 18 ° 18 ' 38 " E, 1080–1100 m, on stump of Picea abies , 2013, Malíček 6090 & Vondrák, hb Malíček. Western Moravia, Žďár nad Sázavou, Žďárské vrchy Protect. Landsc. Area, Cikháj, Žákova hora National Nature Reserve, beech virgin forest, 49 ° 39 ' 18 " N, 15 ° 59 ' 35 " E, 750–800 m, on stump of Fagus , 2012, Malíček 5110 & Syrovátková, hb Malíček. Silesia, Bruntál, Jeseníky Protected Landscape Area, Karlova Studánka, managed spruce forest (c. 100 years old) on N-facing slope in valley of Bílá Opava Brook, 1.8 km ENE of Ovčárna, 50 ° 04 ' 35 " N, 17 ° 15 ' 53 " E, 1170–1180 m, on bark of Picea abies , 2015, Malíček 8490, Kocourková, Vondrák & Zemanová, hb Malíček; ibid., Praděd National Nature Reserve, old-growth spruce forest c. 200 years old on E-facing slope of Mt Vysoká hole (1464 m), 0.2 km WNW of Eustaška hut, 50 ° 03 ' 35 " N, 17 ° 15 ' 12 " E, 1220 m, at base of Picea abies , 2015, Malíček 8563, Kocourková, Palice & Vondrák, hb Malíček. Frýdek-Místek, Beskydy Protected Landscape Area, Ostravice, Mazák National Nature Reserve, old-growth spruce forest with intermixed sycamores on W-facing slope of Mt Lysá hora (1323 m), 49 ° 32 ' 41 " N, 18 ° 26 ' 43 " E, 1200 m, on bark of Picea abies , 2016, Malíček 9743 & Palice, hb Malíček.

Finland, Pohjois-Karjala, Lieksa, Koli National Park (plot 9), East side, old-growth forest, on bark of fallen Picea abies (decay stage 3), 63.1033 ° N, 29.8140 ° E, 2013, Kantelinen 1865 (DNA A 575, apothecia and pycnidia), H. Ibid., on wood of fallen Picea abies (decay stage 4), 2013, Kantelinen 1909 (DNA A 583), H. Ibid., on wood of dead standing Picea abies (decay stage 3), Kantelinen 1685 (DNA A 574), H. Ibid., on wood of fallen Picea abies (decay stage 5), 2013, Kantelinen 2003 (DNA A 594), H. Ibid., on wood of fallen Picea abies (decay stage 3), 2013, Kantelinen 1923 (DNA A 573), H. Etelä-Häme, Hämeenlinna, Evo (plot 8), protected old managed forest, on wood / mosses of a Picea abies stump (decay stage 5), 61.2088 ° N, 25.1363 ° E, 2013, Kantelinen 2899 (DNA A 736). Ibid., on wood of Picea abies , 2013, Kantelinen 1686 (DNA A 768), H. Ibid., Rajakallio, boreal forest on a bouldery slope, forest of Picea , Pinus and Betula , 61 ° 15.27 ' N, 025 ° 06.43 ' E, on bark of rotten wood among boulders, 2007, Palice 11684, conf. Coppins, H. Uusimaa, Tuusula, west of Korso, shaded and dense Picea abies dominated managed forest (plot 2), on wood of a Picea abies stump (decay stage 5), 60.3544 ° N, 25.0322 ° E, 2013, Kantelinen 2643 (DNA A 484), H.

Sweden, Jämtland, Kall par., about 850 m NW of the northwestern tip of Lake Spjuttjärnen, S side of stream Konäsån, on stump of Betula pubescens in old-growth Picea abies forest, 63 ° 34 ' 30 " N, 13 ° 04 ' 05 " E, elev. 440 m, 2022, Svensson 4335, UPS L- 1091180.

Ukraine. Eastern Carpathians, Nadvirna, Bysrytsia, N of hill Skali verkhni, 48 ° 27 ' 48.492 " N, 24 ° 18 ' 35.46 " E, 1233 m, on bark of Picea abies , 2019, Vondrák 22217, PRA.

Figures

Figure 4. Morphological and anatomical features of old and new Micarea osloensis collections A, B old Micarea osloensis A habit, apothecia on soil (Holotype) B apothecial section in water (Palice 11684, H) C – E new Micarea osloensis (Kantelinen 2648, H) C mesopycnidia extruding mesoconidia as a white drop D apothecial section in water E mesopycnidia on dead wood and mosses. Scale bars: Habit 0.5 mm (A, C, E); Apothecial sections 100 µm (B, D).