Asterinaceae, C.G.Hansford, 1946

Jayawardena, Ruvishika S., Ariyawansa, Hiran A., Singtripop, C., Li, Yan Mei, Yan, Jiye, Li, Xinghong, Nilthong, S. & Hyde, Kevin D., 2014, A re-assessment of Elsinoaceae (Myriangiales, Dothideomycetes), Phytotaxa 176 (1), pp. 120-138 : 131-135

Asterinaceae

The family Asterinaceae are small obligately biotrophic ascomycetes that are associated with living leaves of a broad range of angiosperms from tropical and subtropical regions ( Hyde et al. 2013). The important features of Asterinaceae are the superficial, black, web-like colonies that form on the upper and lower surface of leaves, thyriothecia that are closely attached to the host plant cuticle and open at maturity with central star-shaped fissures. The globose bitunicate asci develop vertically in the ascomatal cavity, from the base to the dehiscent opening; this is the important character of the family Asterinaceae which is different from the family Microthyriaceae , where asci are embedded in mucilage and grow horizontally to the host surface and inclined from the thyriothecia rim towards the ostiole. Ascospores are mostly ellipsoidal, 2-celled and hyaline when young and becoming brown at maturity ( Hyde et al. 2013).

Stephanotheca Syd. & P. Syd., The Phillippine Journal of Science: C Botany 9: 178 (1914)

Foliar epiphytes on plants. Sexual state: Ascomata superficial, globose to subglobose, base flattened, black. Upper wall of thick-walled cells, forming a textura porrecta. Hamathecium lacking pseudoparaphyses. Asci 16–31 × 16–25 µm (x = 25 × 19 µm, n = 20), 8-spored, bitunicate, broadly subglobose to obovoid, arranged around outer layer of ascomata within a palisade layer, short pedicellate, apically rounded, without a distinct ocular chamber and ring structures. Ascospores 10–26 × 3–8 µm (x = 16 × 5 µm, n = 5), multi-seriate, irregularly arranged, broadly clavate to ellipsoid, ends rounded, hyaline, 3-septate, without distinct gelatinous sheath. Asexual state: Unknown.

Type: — Stephanotheca micromera Syd. & P. Syd., The Phillippine Journal of Science : C Botany 9(2): 179 (1914) MycoBank No: 215191 ( Fig 5 )

Foliar epiphytes on lower surface of leaves of Taxotrophis ilicifolia . Sexual state: Ascomata 186–266 µm high × 175–251 µm diam. (x = 232 × 212 µm, n = 5), superficial on lower leaf host tissues, globose to subglobose, base flattened, black. Upper wall comprising thick-walled cells, forming a textura porrecta, lower wall poorly developed. Hamathecium lacking pseudoparaphyses. Asci 16–31 × 16–25 µm (x = 25 × 19 µm, n = 20), 8-spored, bitunicate, broadly subglobose to obovoid, arranged around outer layer of ascomata within a palisade layer, short pedicellate, apically rounded, without a distinct ocular chamber and ring structures. Ascospores 10–26 × 3–8 µm (x = 16 × 5 µm, n = 5), multi-seriate, irregularly arranged, broadly clavate to ellipsoid, ends rounded, hyaline, 3- septate, without distinct gelatinous sheath. Asexual state: Unknown.

Material examined:— PHILIPPINES. Palawan, Lake Manguao, on Taxotrophis ilicifolia (Moraceae) , E.D. Merril, April 1913, (S, F6581!, holotype).

Stephanotheca was introduced by Sydow & Sydow (1914) and has only three epithets listed in Index Fungorum (2013). Stephanotheca is characterized by small, black, superficial, rounded bodies with an elevated centre. This genus was originally described as Hemisphaeriaceae , but later placed in Microthyriaceae as it possesses thyriothecia ( Stevens & Ryan 1939, Clements & Shear 1931). Lumbsch & Huhndorf (2007, 2010) placed Stephanatheca in the family Elsinoaceae . Hyde et al. (2013) suggested this genus could be placed in the family Asterinaceae . Stephanotheca forms solitary, gregarious, superficial, black thyriothecia with ovate to oblong, longitudinally radiating asci, and hyaline, one-septate ascospores. Another family which might accommodate it is

132 Phytotaxa 176 (1) © 2014 Magnolia Press JAYAWARDENA ET AL.

Elsinoaceae , but the asci are arranged in a single layer in thyriothecia which have a poorly developed base. Stephanothecaceae may need resurrecting to accommodate Stephanatheca and similar genera if sequence data becomes available. We retain the species in Asterinaceae even though it is atypical.

Myriangiaceae Nyl., Mémoires de la Société Impériale des Sciences Naturelles de Cherbourg 2: 9 (1854)

Saprobic and parasitic on bark, leaves and branches. Producing raised superficial, black ascostromata in which asci develop singly in locules that are generally scattered in ascostromata.

Hemimyriangium J. Reid & Piroz., Canadian Journal of Botany 44: 650 (1966)

Type:— Hemimyriangium betulae J. Reid & Piroz., Canadian Journal of Botany 44: 651 (1966)

This taxon appears to be more similar to Myriangium , the type of family Myriangeaceae in having superficial ascostromata, with a single ascus in each locule, and in the arrangement of locules in the outer layer of the ascostromata and also due to its saprophytic nature. Hemimyriangium is referred to family Myriangiaceae in Dissanayake et al. (2014).

Butleria Sacc., Annales Mycologici 12: 302 (1914)

Type:— Butleria inaghatahani Sacc., Annales Mycologici 12: 302 (1914)

Butleria is a monotypic genus established by Saccardo (1914). von Arx & Müller (1975) referred this genus to Myriangiaceae based on ascostromata and two-celled ascospores. Barr (1979) placed this genus under Elsinoaceae . Kirk et al. (2001), Lumbsch & Huhndorf (2007, 2010), Li et al. (2011) and Hyde et al. (2013) have retained this genus under the family Elsinoaceae . Butleria has similarities with Elsinoaceae in being a parasite on leaves, but differs in having ascostromata on both sides of the leaves, with single asci with a small ocular chamber in each locule and distinct 2-celled, brown ascospores. Butleria shows similarity to the family Myriangiaceae in having globose, single asci in each locule, but differs in having brown ascospores. The genus has been placed in Myriangeaceae by Dissanayake et al. (2014).

Micularia Boedijn, Persoonia 2(1): 67 (1961)

Type:— Micularia merremiae Boedijn, Persoonia 2(1): 67 (1961)

Boedijn (1961) placed this genus in family Saccardiaceae , while Lumbsch & Huhndorf (2007, 2010) placed Micularia in the family Elsinoaceae . This placement has followed by Hyde et al. (2013). Even though it is a parasite on leaves, the inclusion of this genus into Elsinoaceae causes confusion, as it has only 1-septate ascospores, hairs at the apex of the ascostromata and contains a single ascus in each locule. Dissanayake et al. (2014) therefore placed Micularia in Myriangeaceae .

Brefeldiellaceae E. Müll. & Arx , in Müller & von Arx, Beiträge zur Kryptogamenflora der Schweiz 11(no. 2): 148 (1962)

Foliar epiphytes or parasites on leaves of various hosts. Thallus comprising a wide area of radiating cells with darker raised areas under which the ascomata develop and in which saccate to cylindro-clavate asci are formed ( Hyde et al. 2013).

Saccardinula Speg., Anales de la Sociedad cientifica argentina 19: 257(1885)

Type:— Saccardinula guaranitica Sacc Anales de la Sociedad cientifica argentina 19: 257 (1885)

Luttrell (1973) grouped Saccardinula under Saccardinulaceae based on its ascostromata grouping in a radiate, superficial, cellular membrane ( Li et al. 2011). von Arx & Müller (1975) removed this genus to Myriangiaceae and Lumbsch & Huhndorf (2007) placed Saccardinula in the family Elsinoaceae . Li et al. (2011) suggested that Saccardinula can be referred to either Microthyriaceae or Brefeldiellaceae , or Saccardinulaceae can be retained as a distinct family. Saccardinula has globose asci without paraphyses, and forms thyriothecia. Formation of asci and ascomata of Saccardinula are more similar to Brefeldiella which occurs on leaves and has a thallus comprising an area of radiating cells with ascomata ( Reynolds & Gilbert 2005, Wu et al. 2011, Li et al. 2011). Hyde et al. (2013) placed Saccardinula in family Brefeldiellaceae , even though it is a less convincing member of the family as it has globose asci and muriform spores, while the thallus is less-developed.

Dothideomycetes genera incertae sedis

Dothideomycetes is the largest class in Ascomycota. Lumbsch & Huhndorf (2010) in Outline of Ascomycota listed over 150 genera in Dothideomycetes genera incertae sedis ( Thambugala et al. 2014).

Hyalotheles Speg., Revista del Museo de La Plata 15(2): 11 (1908)

Type:— Hyalotheles dimerosperma Speg., Revta Mus. La Plata 15(2): 11 (1908)

Li et al. (2011) and Hyde et al. (2013) suggested that this taxon should be placed in Dothideomycetes genera incertae sedis because it is not a suitable candidate in Elsinoaceae apart from the oblong to ovoid sessile asci.

Chaetothyriaceae Hansf. ex M.E. Barr, Mycologia 71(5): 943 (1979)

Epiphytic or biotrophic on leaves forming mycelium appressed to the host cuticle without penetrating host tissue. Ascomata are surrounded by a thin pellicle of superficial mycelium forming black sooty mould-like areas on leaves that are easily detached from the cuticle ( Chomnunti et al. 2012).

Beelia F. Stevens & R.W. Ryan , Bulletin of the Bernice Pauahi Bishop Museum, Honolulu, Hawaii 19: 71 (1925)

Type:— Beelia suttoniae F. Stevens & R.W. Ryan , Bulletin of the Bernice Pauahi Bishop Museum, Honolulu , Hawaii 19: 71 (1925)

Beelia was introduced by Stevens & Ryan ( Stevens 1925) and placed Beelia in the family Microthyriaceae which was accepted by Petrak (1953). von Arx & Müller (1975) transferred Beelia to Myriangiaceae based on its dimidiate ascomata and muriform ascospores. Hawksworth et al. (1995) referred this genus to family Elsinoaceae where it has been listed by Kirk et al. (2001) and Lumbsch & Huhndorf (2007, 2010). Li et al. (2011) excluded this genus from Elsinoaceae as Beelia is a superficial biotroph on leaf surfaces which is a characteristic of the family Chaetothyriaceae . The species appears to be most similar to Phaeosaccardinula suggesting that this genus should be placed in Chaetothyriaceae .

Sordariomycetes genera incertae sedis

The Sordariomycetes is one of the largest classes in the Ascomycota and the majority of its species are characterized by perithecial ascomata and in-operculate unitunicate asci. Lumbsch & Huhndorf (2010) in Outline of Ascomycota, 119 genera were placed under Sordariomycetes genera incertae sedis ( Zhang et al. 2006).

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Xenodium Syd., Annales Mycologici 33(1/2): 95 (1935)

Type:— Xenodium petrakii Syd., Annales Mycologici 33(1/2): 95 (1935)

Parasitic on leaves. Sexual state: Ascomata scattered, immersed or erumpent, brown to dark brown. Ostiole, with paraphyses. Peridium comprising hyaline cells of textura porrecta. Paraphyses cylindrical to filiform. Asci 8- spored, unitunicate, non- fissitunicate, oblong-clavate, apically rounded, short pedicellate. Ascospores irregularly arranged, cylindrical to filiform, hyaline, 3-septate, hyaline and smooth walled. Asexual state: Xenodiella

Asexual state: Xenodiella Syd., Annales Mycologici 33(1/2): 98 (1935)

Type:— Xenodiella petrakii Syd., Annales Mycologici 33(1/2): 98 (1935)

Parasitic on leaves. Basal stroma globose, cells rounded, yellowish-brown. Conidiophore cells, simple or forkedbranched, branches are always 1-celled. Sterile hyphae distinctively curved. Conidia globose or ovate-round, hyaline.

Xenodium was included in the family Elsinoaceae by Lumbsch & Huhndorf (2007, 2010). Hyde et al. (2013) suggested that this genus should be excluded from Dothideomycetes as it has unitunicate, non-fissitunicate asci. In this paper we suggest that this genus should be placed under Sordariomycetes genera incertae sedis.

Figures

FIGURE 5. Stephanotheca micromera (holotype). a. Material label. b–c. Appearance of thyriothecia on host. d. Squash mount of thyriothecium. e. Cells of upper wall of thyriothecium. f. Arrangement of asci around ascomata. g–i. Asci. j–k. Immature ascospores. Scale bars: b = 500 µm, c = 200 µm, d = 100 µm, f = 50 µm, e–g = 20 µm, h–k = 10 µm.