Karschia Körb., Parerga

Thambugala, Kasun M., Singtripop, Chonticha, Chunfang, Yu, Mckenzie, Eric H. C., Liu, Zuo-Yi, Chukeatirote, Ekachai & Hyde, Kevin D., 2014, Towards a natural classification of Dothideomycetes 7: The genera Allosoma, Austropleospora, Dangeardiella, Griggsia and Karschia (Dothideomycetes incertae sedis), Phytotaxa 181 (1), pp. 34-46 : 38-41

Karschia Körb., Parerga lichenol. (Breslau): 459 (1865)

MycoBank: MB 2545

Lichenicolous. Occurring on calcareous and non-calcareous rocks or loosely associated with algae. Sexual state: Ascomata solitary, scattered, immersed, cleistothecial, ± globose or slightly flattened, black, coriaceous or carbonaceous, lacking ostioles, sometimes with interascal filaments. Peridium wide, generally several layers of lightly pigmented, dark brown to black, thick-walled cells of textura globulosa. Asci 8-spored, scospores, clavate, sessile or short pedicellate. Ascospores crowded, overlapping, hyaline when immature, becoming brown at maturity, oblong to obovate with broadly rounded ends, 1-septate, the upper cells often slightly larger than the lower cells, constricted at the septum. Asexual state: Unknown.

Type species:— Karschia talcophila (Ach.) Körb., Parerga lichenol. (Breslau): 460 (1865) MycoBank: MB 237207. FIG. 2 a–m .

≡ Lecidea talcophila Ach., Lich. Univ. : 183 (1810)

Lichenicolous. Occurring on calcareous and non-calcareous rocks. Sexual state: Ascomata 170–330 µm high, 200−480 µm wide (x = 217 × 360 µm, n=10), solitary, scattered, immersed, cleistothecial, ± globose or slightly flattened, black, carbonaceous, lacking ostioles. Peridium 20−60 µm (x = 33 µm, n=20), wide, generally several layers of lightly pigmented, dark brown to black, thick-walled cells of textura globulosa. interascal filaments not observed. Asci 40−80 × 20−28 µm (x = 57 × 24 µm, n=20), 8-spored, scospores, clavate, sessile or short pedicellate. Ascospores 17−22 × 5.6−7.5µm (x = 18.5 × 6.2 µm, n=30), crowded, overlapping, oblong to obovate with broadly rounded ends, hyaline when immature, becoming brown at maturity, 1-septate, the upper cells often slightly larger than the lower cells, constricted at the septum. Asexual state: Unknown.

Material examined:— ITALY. Lombardia, In alpibus Bormiensibus (S-F203801! holotype) .

Notes:— Karschia was introduced by Körber (1865) and is typified by Karschia talcophila . Various authors have placed this genus under Patellariaceae . Clements (1909) introduced a new genus Epilichen to accommodate the parasitic species which had been assigned to Karschia and the species with definite or evanescent thallus have been placed under Buellia ( Butler 1940) . Hafellner (1979) introduced Colensoniella , Heterosphaeriopsis , Rhizodiscina , Schrakia (Dothideales) and Stratisporella in order to accommodate several Karschia species and accepted only K. talcophila and newly described K. santessonii in Karschia . According to Hafellner (1979), K. talcophila shows similarities with K. santessonii in having stromatic development of pseudothecia, reticular paraphysoids, bitunicate asci and brown ascospores without a germ slit and differs in the size and the wall thickness of the spores. He transferred most Karschia species to Buelliella , Cycloschizon , Dothidea , Eutryblidiella , Gibbera , Poetschia , Pseudodiscus and Rhizogene in the order Dothideales , and others described under Buellia, Epilichen , Rhizocarpon , Rinodina and Dactylospora in the order Lecanorales . Hawksworth et al. (1995) and Courtecuisse et al. (1996) included Karschia in Dothideales genera incertae sedis, while Kirk et al. 2008 and Lumbsch & Huhndorf (2010) classified this genus under Dothideomycetes, genera incertae sedis. Hawksworth et al. (1995) accepted two species in Karschia , while Kirk et al. (2008) included four. Karschia shows similar characters with Lichenotheliaceae in processing lichenicolous, episubstratic or endokapylic, areolate thallus, fertile stromata of various shapes, lacking an ostiole, globose to broadly clavate asci and hyaline to brown, 1-septate scospores ( Hyde et al. 2013). Therefore we tentatively refer Karschia in Lichenotheliaceae pending a molecular investigation.

Pleosporaceae Nitschke, Verh. naturh. Ver. preuss. Rheinl. 26: 74 (1869)

MycoBank: MB 81188

The family Pleosporaceae was introduced by Nitschke (1869) based on the immersed ascomata and presence of pseudoparaphyses, which was assigned to Sphaeriales. Luttrell (1955) placed Pleosporaceae in the order Pleosporales . Multi-gene phylogenetic studies ( Zhang et al. 2012, Hyde et al. 2013) has shown that the familial placement of Pleosporaceae in the order Pleosporales . Hyde et al. (2013) accepted 11 genera in Pleosporaceae . Pleosporaceae species are generally pathogens or saprobes on wood and dead herbaceous stems or leaves. This family is characterized by immersed to erumpent to nearly superficial, ostiolate ascomata, septate, cellular pseudoparaphyses, bitunicate, cylindrical asci and phragmosporous or muriform, brown or pale brown ascospores. Asexual states of Pleosporaceae are reported as coelomycetous or hyphomycetous, with phialidic, annellidic or sympodial blastic conidiogenous cells ( Hyde et al. 2013).

Austropleospora R.G. Shivas & L. Morin , in Morin, Shivas, Piper & Tan, Fungal Diversity 40(1): 70 (2010) MycoBank: MB 512742

Type species:— Austropleospora osteospermi R.G. Shivas & L. Morin , in Morin, Shivas, Piper & Tan, Fungal Diversity 40(1): 70 (2010) MycoBank: MB513237. FIG. 3–4 a–q .

≡ Hendersonia osteospermi Wakef., Bull. Misc. Inf., Kew (5): 165 (1922)

Parasitic on stem and leaves of Chrysanthemoides monilifera (Asteraceae) . Sexual state: Ascomata 75–110 µm high, 130−200 µm wide (x = 100 × 146 µm, n=10), subglobose, sometimes slightly flattened, solitary or in groups, scattered, immersed immediately below the stem epidermis, ostiole 60–90 µm long, with a protruding neck. Peridium 8−18 µm (x = 12 µm, n=10) composed of dark brown to black cells of textura angularis. Hamathecium of 2−3 µm wide, dense, filamentous, anastomosing, aseptate, hyaline pseudoparaphyses. Asci 75−120 × 13−18 µm (x = 92 × 16 µm, n=20) bitunicate, fissitunicate, 6–8-spored, cylindrical to clavate, rounded at the apex and minute ocular chamber with a short, broad, pedicel. Ascospore s 16.5 −21× 6−8.4 µm (x = 18 × 7.7 µm, n=25) biseriate to overlapping uniseriate, ellipsoidal, yellowish brown, muriform, mostly 3 transverse septa, 0–2 longitudinal septa, slightly constricted at median septum, not or very slightly constricted at other septa, apex rounded to slightly tapered, base tapered to rounded, smooth. Asexual state: Conidiomata 75–110 µm high, 100−130 µm wide (x = 88 × 115 µm, n=10) pycnidial, globose, superficial on stem, immersed in the host tissue and becoming erumpent at maturity, globose, dark brown in the erumpent part, with a single ostiole. Conidiomata wall 9−16 wide, brown to reddish brown, thin-walled, comprising several layers with cells of textura angularis. Conidiophores reduced to Conidiogenous cells. Conidiogenous cells 10−12 × 2.5−3.5 µm (x = 11 × 2 µm, n=15), inconspicuously annellidic, discrete, cylindrical. Conidia 14−18 × 4.8−6.5 µm (x = 15.8 × 5.7 µm, n=25), cylindrical to narrowly ellipsoidal, initially hyaline and aseptate, becoming yellowish brown at maturity, mostly transversely 1–3-septate, ends rounded.

Material examined:— AUSTRALIA, Bellinger Head NSW, Kalang river mouth, on stem and leaves of Chrysanthemoides monilifera ssp. rotundata (Asteraceae) . 5 March 2008, L. Morin ( BRIP 52234!, holotype).

Notes:— Austropleospora was introduced by Shivas & Morin (in Morin et al. 2010) in order to accommodate Austropleospora osteospermi on Chrysanthemoides monilifera ssp. rotundata (Asteraceae) . They found Hendersonia osteospermi Wakef. on the same host and identified it as the asexual state of A. osteospermi both in culture and by DNA sequence analysis. Based on ITS sequence analysis Morin et al. (2010) placed Austropleospora under Pleosporales without assigning to any family. Austropleospora is referred to Dothideomycetes genera incertae sedis in Index fungorum (2014). We re-examined and illustrate the type specimen of Austropleospora . Immersed ostiolate ascomata, hyaline anastomosing pseudoparaphyses, cylindrical to clavate asci and yellowish-brown, muriform ascospores suggest that Austropleospora belong to Pleosporaceae . Therefore we tentatively transfer Austropleospora to Pleosporaceae . Multigene phylogenetic analysis is needed in order to clarify the familial placement of Austropleospora in Pleosporales . We synonymize Hendersonia osteospermi under Austropleospora osteospermi based on sexual and asexual state link.

Figures

FIGURE 2. Karschia talcophila (S- F203801, holotype). A. Herbarium material. b–c.Ascostromata on substrate. d–e. Sections through ascomata. f. Peridium. g–i Bitunicate asci. j–m. Ascospores. Scale bars: d = 50 µm, e = 100 µm, f = 50 µm, g–h = 20 µm, j–m = 5 µm.

FIGURE 3. Austropleospora osteospermi (BRIP 52234, holotype) a. Herbarium material b–c. Ascomata on host surface d. Section through ascoma. e Section through ostiole. f. Peridium. g. Pseudoparaphyses h. Immature ascus. i. Mature bitunicate asci. j. Apex of ascus k.. Ascospores. Scale bars: d = 50 µm, e–f = 25 µm, g = 10 µm, h–i = 25 µm, j–k = 15 µm.

FIGURE 4. Austropleospora osteospermi (BRIP 52234, holotype). l. Pycnidia on host. m. Section of pycnidium. n. Pycnidial wall. o. Conidiogenous cells and developing conidia. p–q. Brown 3-septate conidia. Scale bars: m–o = 20 µm, p–q = 5 µm.