Introduction
Thelopsis is a widespread but rarely abundant genus of the Stictidaceae. It occurs equally saxicolous and corticolous, both in tropical and temperate regions, in the latter often on soft bark of old trees. Species of this genus have globose, closed perithecioid apothecia, a hymenium with paraphyses and periphyses, and multispored asci.
So far ten species are known in the genus, only six of which were treated in the revision of the genus (Vězda Reference Vězda1968); the others were described in subsequent papers (Egea & Torrente Reference Egea and Torrente1996; Renobales et al. Reference Renobales, Barreno and Atienza1996; Aptroot et al. Reference Aptroot, Diederich, Sérusiaux and Sipman1997; Moon & Aptroot Reference Moon and Aptroot2009). Some species are known from one country only, but the known ranges of some species have expanded recently when additional reports were published (e.g. Harris Reference Harris1979; McCarthy Reference McCarthy1991; Aptroot & Seaward Reference Aptroot and Seaward1999; Elix et al. Reference Elix, McCarthy and Kantvilas2009).
Topelia (Jørgensen & Vězda Reference Jørgensen and Vězda1984) is a closely related genus of rarely reported species, which differs from Thelopsis mainly by the ascospores that are only 8 per ascus. Four species were originally assigned to the genus Topelia, and they mostly have muriform, broadly ellipsoid ascospores, while the species included in the revision of Thelopsis (Vězda Reference Vězda1968) have at most submuriform ascospores that are ellipsoid, although one of the original Topelia species has submuriform ascospores. Four additional Topelia species have in the meantime been described or transferred into the genus (Mayrhofer Reference Mayrhofer1987; Tretiach & Vězda Reference Tretiach and Vězda1992; Ryan & Lumbsch Reference Ryan, Lumbsch, Nash, Gries and Bungartz2007; Kondratyuk et al. Reference Kondratyuk, Lökös, Tschabanenko, Haji-Moniri, Farkas, Wang, Oh and Hur2013). However, the delimitation between the two genera has become arbitrary with the recent description of the truly muriform Thelopsis muriformis Aptroot & K. H. Moon (Moon & Aptroot Reference Moon and Aptroot2009). Below we describe another intermediate species.
During studies on lichen ecology and diversity by the authors in Atlantic rainforest reserves in the state of Sergipe in the north of Brazil, two undescribed species were encountered, one Thelopsis and one Topelia, and these are described below. The new species were both found in the Parque da Cidade, the only remnant of Atlantic rainforest in the city of Aracaju. From this area, two lichen species had already been described (Cáceres et al. Reference Cáceres, Santos, Mendonça, Mota and Aptroot2013), both of which have been found subsequently in other Atlantic rainforest patches in the state. One of the species was also found in the larger Parque Nacional Serra de Itabaiana, from which few lichens have so far been reported (Cáceres Reference Cáceres2007) but which is very species rich, with about 375 recorded. A further new Topelia species is described from the subtropical Chaco region in Argentina.
Because several new species have been recently described in these two genera, an artificial world key to all currently known species of Thelopsis and Topelia is given, with the currently known distribution ranges. The key is based on Breuss & Schultz (Reference Breuss and Schultz2007) which, however, only includes Thelopsis species. Although the delimitation between Thelopsis and Topelia has increasingly become arbitrary, the genera are not formally synonymized here pending further evidence.
Material and Methods
Identification and descriptive work was carried out in Itabaiana, Universidade Federal de Sergipe, using a Leica EZ4 stereomicroscope and a Leica DM500 compound microscope, and also in Soest using an Olympus SZX7 stereomicroscope and an Olympus BX50 compound microscope with interference contrast, connected to a Nikon Coolpix digital camera. Sections were mounted in tap water, in which all measurements were also taken. The specimens from this study are preserved in ISE or CTES, with duplicates in ABL. The chemistry of the type specimens was investigated by spot reactions with KOH, C and Pd, and by thin-layer chromatography (TLC) using solvent A (Orange et al. Reference Orange, James and White2001).
The New Species
Thelopsis cruciata Aptroot & M. Cáceres sp. nov.
MycoBank No.: MB 809571
Corticolous Thelopsis with olive-green thallus, immersed red-brown perithecia and c. 100 cruciate ascospores per ascus, 7–10×4–7 µm.
Type: Brazil, Sergipe, Aracaju, Parque da Cidade Governador José Rollemberg Leite, 10°52′57″S, 37°03′10″W, on bark of tree, 75 m alt., 15 September 2013, M. Cáceres & A. Aptroot 18225 (ISE—holotype; ABL—isotype).
A & B, Thelopsis cruciata, isotype. A, habitus; B, multispored asci (left), ascospores (right); C, D & G, Topelia argentinensis, isotype. C, habitus; D, asci with 8 ascospores; G, ascospore. E & F, Topelia tetraspora, isotype. E, habitus; F, ascospore. Scales: A, C & E=0·1 mm; B (left) & D=25 μm; B (right), F & G=10 μm. In colour online.
Thallus crustose, corticate, dull or slightly shiny, olive-green to olive-brown, smooth to somewhat granular, not surrounded by prothallus.
Perithecia numerous, dispersed, mostly immersed in the thallus or partly in the bark, globose, 0·25–0·35 mm diam., mostly covered by thallus, only a small area around the ostiole visible from above as a red-brown dot. Ostiole inconspicuous. Wall mostly hyaline, brownish around the ostiole, c. 50 µm thick. Hymenium not inspersed, IKI+ pale blue; paraphyses unbranched, sparse, apices not swollen; periphyses unbranched, numerous. Asci containing c. 50–100 ascospores, 80–95×19–25 µm. Ascospores hyaline, cruciate septate with generally 4 locules, globose to ellipsoid, 7–10×4–7 µm.
Pycnidia not observed.
Chemistry
No spot reactions. TLC: no substances.
Ecology and distribution
On rough bark of trees in Atlantic rainforest. Known only from Brazil.
Discussion
This new species is internally well characterized by the unique cruciate ascospores, which are otherwise unknown in the family, and occur in the order Ostropales or otherwise only in distoseptate ascospores. In most other characters it is close to Thelopsis rubella Nyl.
Additional material examined. Brazil: Sergipe: Aracaju, Parque Nacional Serra de Itabaiana, 250 m alt., 2013, M. Cáceres & A. Aptroot 18253 (ISE, ABL).
Topelia argentinensis Aptroot, L. I. Ferraro & M. Cáceres sp. nov.
MycoBank No.: MB 809572
Corticolous Topelia with a verrucose, partly almost isidiate, greenish grey thallus, immersed pinkish perithecia and 8 uniseriate muriform ascospores per ascus, 12–17×7–11 µm.
Type: Argentina, Chaco, 15 km W of Presidencia Roca, 26°06′28″S, 59°47′20″W, on bark of tree, 877 m alt., 27 February 2013, L. I. Ferraro, A. Aptroot & M. E. S.Cáceres 10889 (CTES—holotype; ABL—isotype).
Thallus crustose, corticate, dull or slightly shiny, greenish grey, uneven to verrucose, the verrucae partly so discrete that they are almost low isidia c. 0·05 mm diam., not surrounded by prothallus.
Perithecia numerous, dispersed, mostly immersed in the thallus, globose, 0·15–0·25 mm diam., mostly covered by thallus, pink in surface view although only a relatively small area around the ostiole is usually visible from above. Ostiole inconspicuous. Wall hyaline in section, c. 50 µm thick. Hymenium not inspersed, IKI+ blue; paraphyses unbranched, sparse, apices not swollen; periphyses unbranched, numerous. Asci containing 8 uniseriate ascospores, 90–115×10–13 µm. Ascospores hyaline, muriform, 4–6×1–2-septate, with 10–16 locules visible in surface view, broadly ellipsoid, 12–17×7–11 µm.
Pycnidia not observed.
Chemistry
No spot reactions. TLC: no substances.
Ecology and distribution
On rough bark of trees in semi-deciduous subtropical forest. Known only from Argentina.
Discussion
This new species is in most characters close to Topelia jasonhurii L. Lökös et al. (Kondratyuk et al. Reference Kondratyuk, Lökös, Tschabanenko, Haji-Moniri, Farkas, Wang, Oh and Hur2013), which was recently described from Korea. That species mainly differs by the brown to black exciple in the ostiolar region.
Topelia tetraspora Aptroot & M. Cáceres sp. nov.
MycoBank No.: MB 809573
Corticolous Topelia with a c. 0·1–0·6 mm thick layer of coralloid to usually flattened, irregularly palmately branched isidia c. 0·05 mm diam., ascospores muriform, 15–19×2–6-septate, ellipsoid, 39–50×11–16 µm, only up to 4 per ascus maturing.
Type: Brazil, Sergipe, Aracaju, Parque da Cidade Governador José Rollemberg Leite, 10°52′57″S, 37°03′10″W, on bark of tree, 75 m alt., 15 September 2013, M. Cáceres & A. Aptroot 18228 (ISE—holotype; ABL—isotype).
Thallus crustose, corticate, dull or slightly shiny, mineral grey, mostly covered with a c. 0·1–0·6 mm thick layer of coralloid to usually flattened, irregularly palmately branched isidia c. 0·05 mm diam., not surrounded by prothallus.
Perithecia sparse, not equally dispersed, superficial on the thallus, mostly between but also emergent from the isidia, globose, 0·25–0·50 mm diam., not covered by thallus, dark brown to nearly black, often in various shades on one perithecium. Ostiole inconspicuous. Wall in section mostly brown on the outside, c. 50 µm thick. Hymenium not inspersed, IKI−; paraphyses unbranched, numerous, apices not swollen; periphyses unbranched, numerous. Asci initially containing 8 irregularly biseriate ascospores, but only up to 4 maturing (often only 2), 95–125×19–29 µm. Ascospores hyaline, muriform, 15–19×2–6-septate, ellipsoid, 39–50×11–16 µm.
Pycnidia not observed.
Chemistry
No spot reactions. TLC: no substances.
Ecology and distribution
On smooth bark of trees in Atlantic rainforest. Known only from Brazil.
Discussion
This is the only species known in the genus with real isidia. The previous species has tiny low warts that are nearly, but not really, isidia. It is therefore unmistakable and not likely to be confused with any other species.
World key to the species of Thelopsis and Topelia
For all species, ascospore septation and measurements are given. This key also mentions the world distribution and the substratum if it is not tree bark.
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1 Ascospores simple, minute, 4–6×3–4 µm; perithecia yellow; Europe, USA (Virginia) ... Thelopsis flaveola Arnold
Ascospores transversely septate to muriform, larger; perithecia not yellow ... 2
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2(1) Ascospores transversely septate ... 3
Ascospores cruciate, submuriform or muriform ... 10
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3(2) Ascospores 1-septate ... 4
Ascospores 3-septate ... 8
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4(3) Thallus byssoid; spores 9–13×4–5 µm; Australia, New Guinea, Thailand ... Thelopsis byssoidea Diederich
Thallus not byssoid ... 5
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5(4) Perithecia immersed in strongly convex to hemispherical thalline warts; spores 12–18×6–8 µm; on bark but occasionally on rock, Europe, North Africa, Asia (Hong Kong), Australia, North America ... Thelopsis isiaca Stiz.
Perithecia not in thalline warts, entirely below the level of thallus surface, or protruding but not covered by a thalline layer ... 6
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6(5) Ascospores 7–11×4–5 µm; endolithic, Spain ... Thelopsis foveolata Renob. & Barreno
Ascospores mostly longer; thallus epilithic ... 7
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7(6) Ascospores 14–19×4–5 µm; perithecia immersed in the thallus, pale; on rock, Socotra ... Thelopsis paucispora Breuss & M. Schultz
Ascospores 10–14×5–6 µm; perithecia protruding, red-brown; on rock, South Africa ... Thelopsis obscura Egea & Torrente
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8(3) Perithecia reddish brown; spores 12–18×5–6 µm; on bark but occasionally on rock, Europe (e.g. Ukraine), Asia, North America ... Thelopsis rubella Nyl.
Perithecia at least in the upper part brown-black or black ... 9
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9(8) Perithecia smooth, dark in upper part; ascospores 18–25×4–5 µm; on limestone, Central Europe ... Thelopsis lojkana Nyl.
Perithecia warty, dark throughout; ascospores 11–20×4–7 µm; on mosses and plant debris, Europe, USA (Michigan) ... Thelopsis melathelia Nyl.
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10(2) Ascospores cruciate or submuriform, with less than 10 locules ... 11
Ascospores muriform, with more than 10 locules ... 13
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11(10) Ascospores cruciate, with generally 4 locules, 7–10×4–7 µm, c. 100 per ascus; Brazil ... Thelopsis cruciata Aptroot & M. Cáceres
Ascospores submuriform, with more than 4 locules ... 12
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12(11) Ascospores 40–80 per ascus, 9–14×5–7 µm; India, North America, here reported for the first time from South America: Guyana, Georgetown, University campus, February 1985, A. Aptroot 15702 (BR) ... Thelopsis inordinata Nyl.
Ascospores 8 per ascus, 9–14×5–7 µm; on limestone, Southern Europe ... Topelia heterospora (Zahlbr.) P. M. Jørg. & Vězda
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13(10) Ascospores c. 50 per ascus, 17–20×8–10 µm; Korea ... Thelopsis muriformis Aptroot & K. H. Moon
Ascospores 8 (or less) per ascus ... 14
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14(13) Perithecia dark brown to nearly black; ascospores 39–50×11–16 µm, only up to 4 per ascus maturing; thallus with isidia; Brazil ... Topelia tetraspora Aptroot & M. Cáceres
Perithecia pale brown to pink or colourless; thallus not isidioid ... 15
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15(14) Perithecia opening with a wide pore ... 16
Perithecia remaining closed, only with a punctiform ostiole ... 18
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16(15) Ascospores globose to broadly ellipsoid, 13–20×10–13 µm; southern USA (Arkansas, Louisiana, Missouri) ... Topelia aperiens P. M. Jørg. & Vězda
Ascospores ellipsoid, over 20 µm long ... 17
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17(16) Exciple 30–60 µm wide, brown to black outside, with dark granules; ascospores (20–) 23–28(–32)×9–12 µm; California ... Topelia californica P. M. Jørg. & Vězda
Exciple 70–80 µm wide, pale to yellowish brown outside, without dark granules; ascospores 20–26–(28)×11–14 µm; on limestone, California ... Topelia gyalectodes (Nyl.) B. D. Ryan & H. T. Lumbsch
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18(15) Ascospores>19 µm long ... 19
Ascospores<18 µm long ... 21
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19(18) Thallus grey; ascospores 25–33×14–19 µm; immersed in limestone, Cuba, Mexico ... Topelia brittonii (Riddle) Mayrh.
Thallus green; in or on bark, on mosses or superficial on limestone ... 20
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20(19) Perithecia not immersed in the substratum or the thallus; thallus pinkish; ascospores (20–)22–25(–28)×12–14 µm; on bark, mosses or limestone, Mediterranean Europe, New Zealand, Lord Howe Island ... Topelia rosea (Servít) P. M. Jørg. & Vězda
Perithecia immersed in the substratum or the thallus; thallus grey or green; ascospores 20–30×8–12 µm; immersed in bark, Italy ... Topelia nimisiana Tretiach & Vězda
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21(18) Exciple partly brown, at least near the ostiole and below the hymenium; ascospores (11–)12–15(–17)×9–11 µm; Korea ... Topelia jasonhurii L. Lökös et al.
Exciple pinkish, hyaline in section; ascospores 12–17×7–11 µm; Argentina ... Topelia argentinensis Aptroot et al.
MESC thanks the CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) for a research grant (Processo 311706/2012-6). CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) is thanked for a Masters scholarship to COM. AA is grateful to the Stichting Hugo de Vries-Fonds for travel support.
