uring fieldwork in temperate deciduous woodlandin south Sweden, the first author frequently en-countered an unknown loculoascomycete with poly-

sporous asci on hard, exposed heartwood of branches of theoaks Quercus robur L. and Q. petraea (Matt.) Liebl. Duringa stay in Japan a similar species was then found on the samekind of wood of Quercus mongolica var. grosseserrata (Bl.)Rehd. & Wils. Both. The Swedish and Japanese material wassubsequently identified to the genus Moristroma and the twonew species are described below as M. quercinum and M. ja-ponicum. Additional finds of M. quercinum were registeredby the second author in a project on bark- and wood-inhabit-ing fungi on Quercus in northern Europe.

Besides describing and illustrating the two new species,we aim to elucidate the systematics of Moristroma. The genusMoristroma was erected by ROMERO & SAMUELS (1991) to ac-commodate a single species, M. polysporum, on Eucalyptusin Argentina. ROMERO & SAMUELS (1991) referred their newgenus to Pleosporales sensu BARR (1987), and tentatively tothe Dacampiaceae. ERIKSSON et al. (2004) instead assignedMoristroma to the Teichosporaceae (Dothideomycetes),while treating the Dacampiaceae in Dothideomycetes and

Chaetothyriomycetes incertae sedis. To study the systematicplacement of Moristroma further, we wanted to perform amolecular phylogenetic analysis of the ITS and partial LSUregion of rDNA with several representatives of Dothideomy-cetes and Chaetothyriomycetes.

Material and methods

Morphological analyses

The morphological study of Moristroma quercinum is basedon Danish (1), Lithuanian (1), and Swedish collections (28).The investigation of M. japonicum is based on the Japaneseholotype. The holotypes of both species and the collections ofNordén are preserved at the University of Göteborg (in herb.GB) and the specimens of Sunhede at the School of LifeSciences, University of Skövde (in herb. Sunhede).

We tried to loan type material of M. polysporum from theU.S. National Fungus Collections (BPI), but they would notallow a loan due to the scantiness of the material (Erin B.McCray, Herbarium Manager, in lit.). Because the features ofMoristroma are unique, the risk of applying an erroneous ge-neric placement of the species was judged as negligable. Thisview was further supported by correspondence with M.E. BarrBigelow, Canada.

Measurements and drawings of ascostromata and pycnidiarefer to dry herbarium specimens. Tissue sections (cut witha thin razor blade), were mounted in 2 % KOH. Melzersreagent was used to test amyloidity, and cotton blue (lacto-phenol with cotton blue) was used for staining. Measurementsof asci, hyphae, spores and conidia have been recorded from

New species of Moristroma (Ascomycetes) and phylogenetic position of the genus

Björn NORDÉN1,*, Stellan SUNHEDE2, and Ellen LARSSON1

The loculoascomycete Moristroma quercinum sp. nov. and Moristroma japonicum sp. nov. are described from NorthernEurope (Denmark, Lithuania, Sweden) and Japan, respectively. M. quercinum is reported from wood of Quercus robur andQ. petraea, and M. japonicum is reported from wood of Quercus mongolica var. grossoserrata. Ascostromata of bothspecies were found on hard heartwood of attached or shed branches. The two new species differ from the type species of thegenus, M. polysporum, by the presence of pycnidia, and by the size of ascostromata, asci and ascospores. Drawings illust-rate ascostromata, pycnidia, asci, hamathecium and ascospores of the two new species. A phylogenetic analysis suggeststhat Moristroma belongs to the Chaetothyriomycetes, rather than to the Dothideomycetes as previously suggested.

Taxonomical novelties: Moristroma quercinum B. Nordén, Moristroma japonicum B. Nordén

Key words: Chaetothyriomycetes, Dothideomycetes, parsimony analysis, internal transcribed spacer, large sub-unit, pycnidia, Quercus

Mycological Progress 4(4): 325–332, November 2005 325

1 Department of Systematic Botany, Göteborg University, Box 461,SE 405 30 Göteborg, Sweden. E-mail: bjorn.Nordén@botany.gu.se.

2 School of Life Sciences, University of Skövde, Box 408, SE-541 28Skövde, Sweden. E-mail: stellan.sunhede@.his.se

* Corresponding author: Dr. Björn Nordén: Department of Syste-matic Botany, Göteborg University, Box 461, SE 405 30 Göteborg,Sweden. E-mail: bjorn.Nordén@botany.gu.se.

© DGfM 2005

D

326 NORDÉN, SUNHEDE & LARSSON: Taxonomy and phylogeny of Moristroma (Ascomycetes)

© DGfM 2005

KOH-mounts and approximated to the nearest 0.5 µm, exceptfor the small spores and conidia where tenths of a micrometerwere estimated. Measurements of the ascostroma wall refersto outwarding walls of ascostromata. Between loculi in multi-loculate asostromata the wall may be thinner or thicker. Thefigures for micromorphological measurements comprise theextremes in parentheses and the usual range of measures, basedon n = 50 measurements for each variable.

M. quercinum was cultured on Malt Extract Agar (1.25 %malt extract, 1 % agar). Pure cultures were obtained by allow-ing fresh ascostromata to sporulate on the agar surface. Thecultures were grown at 14 ºC on 5 cm petri dishes.

Minute pieces of wood with single ascostromata were soak-ed in sterile water and glued to lids with ostioles pointingdown. The lids were placed back on petri dishes overnight,and subsequently replaced by sterile lids.

Molecular analyses

DNA was extracted from the contents of loculi of air-driedascostromata of the two Moristroma species, using a modi-fied 2 % CTAB method (LARSSON & HALLENBERG 2001). Thecomplete internal transcribed spacer (ITS) region and appro-ximately 900 bases of the 5´end of the large sub-unit (LSU)nuclear rDNA were amplified using primers ITS1, ITS4 (WHI-TE et al. 1990), LR0R, and Lr7 (VILGALYS & HESTER 1990).Amplification and sequencing were performed as described inLARSSON & HALLENBERG (2001). Sequences were edited andassembled using Sequencher 3.1 (Gene Codes Corp.) and havebeen deposited in GenBank (AY254051 and AY254052).

The primary purpose of the molecular analysis was spe-cies discrimination. The ITS region was selected as the spacerswithin the region often exhibit a relatively high sequence sub-stitution rate, allowing for discrimination between closely re-lated taxa, and giving support when describing new species(KÕLJALG & LARSSON 1998; LARSSON & LARSSON 1998). TheLSU is usually too conserved to separate closely related spe-cies and was included here in order to study the relationshipswith more distantly related taxa.

In an effort to study the phylogenetic placement of Mori-stroma, GenBank was searched for relevant sequences of thesame molecular region. A BLAST search returned sequencesof Capronia spp as the best matches to M. quercinum and M.japonicum, suggesting a possible relationship between theseand species of Capronia. Capronia was treated in the Chaeto-thyriomycetes by GRUBE & WINKA (2002) and ERIKSSON etal. (2004), and to test the affinities of Moristroma, sequencesof both chaetothyriomycetes (including Capronia) and dothi-deomycetes were selected in addition to one eurotiomyceteand one lecanoromycete. According to ERIKSSON et al. (2004),Byssothecium and Moristroma both belong to the Teichospo-raceae, and a Byssothecium sequence was included in the ana-lysis. Dothidea sambuci was selected as out group based onLUTZONI et al. (2004). The sixteen accessed sequences arelisted in Tab. 1.

The sequences were manually aligned using the data editorin PAUP* 4.0 b2 (SWOFFORD 2000). Gaps for insertion-dele-tion events were introduced to aid in the alignment. Searchesfor most parsimonious trees were performed using the ex-haustive search option in PAUP*. All transformations wereconsidered unordered and equally weighted. Gaps were treatedas missing data. Bootstrapping was performed using 1000heuristic search replicates with 100 random taxon addition se-quence and TBR swapping.

Results

Taxonomy

Moristroma quercinum B. Nordén, sp. nov.Fig. 1–18, 35–38

Etymology: “quercinum”, growing on Quercus.

Ascostromata 0.25–1.5 (3) × 0.25–1 mm; semiimmersa vel super-ficialia, nigra, pulvinata, rotunda vel oblonga, (1) 3–10 (20)-loculata.Loculi globosi, 210–375 µm diam. Hymenia non amyloidea, rariusamyloidea. Asci anguste ellipsoidei, (107) 112–160 (176) × (14)16–24 (28) µm, bitunicati, fissitunicati, polyspori (> 1000). Asco-sporae ellipsoideae vel cylindricae, (2.2) 2.5–3.0 (3.2) × 1–1.2 (1.3)µm, unicellulares, eguttulatae vel guttulatae, hyalinae, laeves. Con-textus inter ascos compositus per filamenta, hyalina, ramosa, 1–2 µmcrassa. Peridium (25) 30–50 (60) µm latum, carbonaceum, in sec-tione olivaceum, textura angularis composita, lumina (2.4) 3.5–4.8(6.4) × (2.4) 3.0–3.5 (4.0) µm. Pycnidia inter vel super ascostromataformata, globosa, conica vel pyriformia, nigra, 100–180 × 75–150 µm,rostro 10–60 × 20–40 µm. Paries 20–30 µm latus, carbonaceus, insectione olivaceus, textura globulosa composita, lumina (3.2) 4.5–5.6(7.2) µm. Conidiophora absentia. Cellulae conidiogenea discretae,determinatae, ampulliformes, pallide olivaceae (2.2) 2.4–2.8 (3.2) ×(1.4) 1.6–1.8 (2.0) µm, ex cellulis interioribus conidiomatum for-mata. Conidia (2.0) 2.4–2.8 (3.2) × 0.9–1.1 µm, holoblastica, cylin-drica, unicellularia, eguttulata, hyalina, laevia. Crescit in ligno duroQuercus roboris.

Holotypus: SWEDEN: Västergötland prov: Östad par., Östad Säteri,Djurgården, on branch of Q. robur, 11 May 2001, Nordén 1678(herb. GB).

Ascostromata superficial to semi-immersed, black, ± pulvi-nate, ± circular to oblong in outline depending on the numberof loculi, 0.25–1.5 (3) × 0.25–1 mm, consisting of partly orcompletely merged locular bodies (Fig. 1–2, 5–8) or denselyclustered locular bodies merely joined at their bases (Fig. 3,4). Loculi rounded (1) 3–10 (20) per ascostroma, 210–375 µmdiam (Fig. 5–8). Locular bodies without apical papilla but witha prominent ostiole (Fig. 1, 4, 6–8). Ascostroma wall (25)30–50 (60) µm thick, carbonaceous, of textura angularis, lu-mina (2.4) 3.5–4.8 (6.4) × (2.4) 3.0–3.5 (4.0) µm, with greenand brown tinges in section (in both water and KOH). Ascinarrowly ellipsoid, sometimes clavate or almost tubular (107)112–160 (176) × (14) 16–24 (28) µm, polysporous (> 1000),bitunicate and fissitunicate (Fig. 35–37), non-amyloid. Asco-spores ± oblong to slightly reniform, (2.2) 2.5–3.0 (3.2) ×1–1.2 (1.3) µm, unicellular, eguttulate or guttulate, smooth,hyaline, non-amyloid (Fig. 38). Pseudoparaphyses 1–2 µm

Mycological Progress 4(4) / 2005 327

© DGfM 2005

wide, branched (Fig. 37). Pycnidia found on or between asco-stromata (Fig. 1, 3, 4, 7), globose to depressed globose, oralmost conical to pyriform (Fig. 10–18), black, 100–180 ×75–150 µm, rostra 10–60 × 20–40 µm. Pycnidial wall 20–30 µmthick, carbonaceous, of textura globulosa, with green andbrown tinges in section, lumina (3.2) 4.5–5.6 (7.2) µm. Coni-diophores absent. Conidiogenous cells discrete, determinate,ampulliform, light brownish-greenish, (2.2) 2.4–2.8 (3.2) × (1.4)1.6–1.8 (2.0) µm, formed from the inner cells of the conidio-matal wall. Conidia (2.0) 2.4–2.8 (3.2) × 0.9–1.1 µm, holoblas-tic, cylindrical, unicellular, eguttulate, smooth, and hyaline.

Cultural characters: M. quercinum produced cultures withsparse white aerial mycelium and pycnidia identical to thosein collections. Cultures completely covered the agar after fourweeks and then started to produce pycnidia.

Habitat and distribution: Ascostromata develop on exposed,hard heartwood of Quercus robur. The species is common onstill attached or shed branches of old oak trees, and can alsobe found on old stumps. Fresh stromata can apparently befound all year round.

Other specimens examined: DENMARK: Jylland, Hald Egeskov,on branch of Quercus robur, May 1999, Nordén 1664. LITHUANIA:Utena district, Azuolija forest, forest square No 44, area No 9. Ondecorticated branch of Quercus robur in old oak-dominated stand,Aug 2001. Leg. R. Ir‰enaite, Nordén 1675. SWEDEN: Bohuslänprovince: Skredsvik parish, Gullmarsberg, on branch of Quercus ro-bur, XI.2002, Nordén 1678. Halland prov.: Fjärås par., Rossared, onbranch of Q. robur, X.1996, Nordén 1661. Släp par., Hördalen na-ture reserve, on branch of Q. robur, IV.2001, Nordén 1679. Ölandprov.: Borgholm par., Borgehage, on branch of Q. robur, X.1996,

Nordén 1680. Östergötland prov.: Åtvid par., Åtvidaberg key habi-tat area, on oak branch, V.2001, Nordén 1670 and 1671. Skåne prov.:Torekov par., Hallands Väderö, Söndre skog, on fallen branch ofQuercus, 1990, Sunhede 7681 Småland prov.: Fågelfors par.,Blanksö, on Quercus log, Aug 1996, Nordén 1660. Långemåla par.,Hornsö, Getebro nature reserve, on oak branch, IV.2001, Nordén1666. Uppland prov .: Ljusterö par., Svartsö. On branch of Q. robur,1.X.2002, Sunhede 7683. Västergötland prov.: Medelplana par.,Hjelmsäter, on Quercus log, III.1997, Nordén 1663. Östad par., ÖstadSäteri, on hard oak branch in pasture, V.2001, Nordén 1677.

Moristroma japonicum B. Nordén, sp. nov.Fig. 19-34, 39-43

Etymology: After Japan, the country from which this species isknown.

Ascostromata 0.3–3 (5.5) × 0.3–1 mm; semiimmersa vel superficia-lia, nigra, pulvinata, lineata, (1) 5–15 (30)-loculata. Loculi globosi,150–250 (280) µm diam. Hymenia non amyloidea. Asci angusteellipsoidei, (111) 123–174 (184) × (13) 15–22 (25) µm, bitunicati,fissitunicati, polyspori (> 1000). Ascosporae ellipsoideae vel cylin-dricae, (2.2) 2.5–3.5 (4.0) × (0.9) 1–1.1 (1.2) µm, unicellulares, egut-tulatae vel guttulatae, hyalinae, laeves. Contextus inter ascos com-positus per filamenta, hyalina, ramosa, 1–2 µm crassa. Peridium car-bonaceum, (30) 40–60 (80) µm latum, in sectione olivaceum, texturaangularis composita, lumina (3.2) 4.8–6.4 (8.8) × 3.2–4 (4.8) µm.Pycnidia inter vel super ascostromata formata, ellipsoidea, conicavel pyriformia, nigra, 100–140 × 50–140 µm, rostro 0–20 × 20 µm.Paries 20–30 µm latus, carbonaceus, textura globulosa, in sectioneolivaceus, lumina (4.0) 4.8–5.6 (6.4) µm. Conidiophora absentia. Cel-lulae conidiogenea discretae, determinatae, ampulliformes, dilutesolivaceum (3.0) 3.4–3.9 (4.9) × (2.4) 2.8–3.2 (4.0) µm, ex cellulis in-terioribus conidiomatum formata. Conidia (2.0) 2.4–2.8 (3.0) ×0.8–1.0 µm, holoblastica, cylindrica, unicellularia, eguttulata, hyalina,laevia. Crescit in ligno duro Quercus mongolicae var. grossoserratae.

Species Accession number Systematic placement

Byssothecium circinans AY016357 Teichosporaceae; D

Capronia mansonii AY004338 Herpotrichiellaceae; C

C. pilosella AJ232940 Herpotrichiellaceae; C

C. pulcherrima AF050256 Herpotrichiellaceae; C

C. villosa AF050261 Herpotrichiellaceae; C

Dermatocarpon luridum AY640948 Verrucariaceae; C

Dothidea sambuci AY544681 Dothideaceae; D

Farlowiella carmichaeliana AY541492 Hysteriaceae; D

Glyphium elatum AF346420 C inc. sedis

Melanomma radicans U43479 Melanommataceae; D

Mycosphaerella heimioides AF309577 Mycosphaerellaceae; D et C inc. sedis

Ostropa barbara AY584642 Stictidaceae; L

Penicillium commune AY213617 Trichocomaceae; E

Phaeosphaeria avenaria ssp. avenaria AY152612 Phaeosphaeriaceae; D

Pyrenula cruenta AF279407 Pyrenulaceae; position uncertain

Sydowia polyspora AY152616 Dothioraceae; D et C inc. sedis

Verrucaria pachyderma AF356668 Verrucariaceae; C

Tab. 1: Sequences obtained from GenBank and used in the phylogenetic analysis. The systematic placement of the speciesfollows ERIKSSON et al. (2004); C = Chaetothyriomycetes, D = Dothideomycetes, E = Eurotiomycetes, L = Lecanoromycetes

328 NORDÉN, SUNHEDE & LARSSON: Taxonomy and phylogeny of Moristroma (Ascomycetes)

© DGfM 2005

Holotypus: Japan: Tottori-ken: Mt. Daisen. On hard branch (heart-wood), 10 cm diam, of old Quercus mongolica var. grossoserrata,in mountain forest dominated by Fagus crenata Blume, alt. ca 700msm, Nov 2001, Nordén 1674 (GB).

Ascostromata superficial to semi-immersed, black, ± pulvi-nate, oblong to linear in outline depending on the number ofloculi, 0.3–3 (5.5) × 0.3–1 mm, consisting of partly or com-pletely merged locular bodies (Fig. 19–21, 23, 24). Loculirounded, (1) 5–15 (30) per ascostroma, 150–250 (280) µmdiam. Locular bodies without apical papilla but with a pro-minent ostiole (Fig. 19, 21, 23, 24). Ascostroma wall (30)40–60 (80) µm thick, carbonaceous, of textura angularis andwith green and brown tinges in section (in both water andKOH), lumina (3.2) 4.8–6.4 (8.8) × 3.2–4 (4.8) µm, Fig. 40.Asci narrowly ellipsoidal, sometimes clavate, (111) 123–174(184) × (13) 15–22 (25) µm, polysporous (> 1000), bitunicateand fissitunicate (Fig. 41–43), non-amyloid. Ascospores ± cy-lindrical to ellipsoid or slightly reniform, (2.2) 2.5–3.5 (4.0)

× (0.9) 1–1.1 (1.2) µm, unicellular, eguttulate or guttulate,smooth, hyaline, non-amyloid (Fig. 39). Pseudoparaphyses1–2 µm wide, branched. Pycnidia found on or between theascostromata (Fig. 23, 30), ellipsoidal (Fig. 25–27, 29), blunt-ly conical (Fig. 28, 30, 33, 34), or pyriform (Fig. 23, 31, 32),black, 100–140 × 50–140 µm, rostra 0–20 x 20 µm. Pycnidialwall 20–30 µm, carbonaceous, textura globulosa, with greenand brown tinges in section, lumina (4.0) 4.8–5.6 (6.4) µm.Conidiophores absent. Conidiogenous cells discrete, determi-nate, ampulliform, light brownish-greenish (3.0) 3.4–3.9 (4.9)× (2.4) 2.8–3.2 (4.0) µm, formed from the inner cells of theconidiomatal wall. Conidia (2.0) 2.4–2.8 (3.0) × 0.8–1.0 µm,holoblastic, cylindrical, unicellular, eguttulate, smooth, andhyaline.

Habitat and distribution: Ascostromata were found on hardheartwood of still attached and shed branches of Quercusmongolicae var. grossoserratae. Known only at the type lo-cality.

Figs 1–18: Moristroma quercinum macromorphology. – 1-9. Ascostromata. – 1-3, 9. Side views. – 4. From above. – 3, 4. Withtwo pycnidia (py) attached at the side of one ascostroma and between two ascostromata, respectively. – 5-8. Vertical sectionsshowing loculi. – 5. Ascostroma emerging from a crack in the wood (wo). – 7. With a sectioned pycnidium (py). – 8. Bilocu-late ascostroma. – 9. Uniloculate ascostroma. – 10-18. Pycnidia, side views. – 14.Young pycnidium. – 1, 3, 8-18. Nordén 1685.– 2, 5. Nordén 1684. – 6, 7. Holotype. – Del. Stellan Sunhede.

Mycological Progress 4(4) / 2005 329

© DGfM 2005

Molecular analysis

The two Moristroma species were differentiated by 6 substi-tutions and 10 insertion/deletion events in the ITS region, ofwhich 7 were by a single nucleotide within multiple T, C orA regions (in total 2.6 % nucleotide divergence).

The length of the aligned dataset, using Dothidea sam-buci as out group, was 1700 bp. Of these, 708 characters,mainly from the ITS regions, were excluded because of am-biguities in the alignment. The phylogenetic analysis gene-rated two most parsimonious trees, with similar topology,based on 194 parsimony-informative characters (tree length= 642; consistency index = 0.5704; retention index = 0.5850).Tree number two was selected and is presented as a phylo-gram and bootstrap values are indicated (Fig. 44).

The tree topology revealed that the two Moristroma speciesclustered within a clade consisting of Capronia, Dermato-carpon, Glyphium and Verrucaria, with 76 % bootstrap sup-port, all of which appeared in the Chaetothyriomycetidaeclade in the analysis by LUTZONI et al. (2004). The two Mori-stroma species cluster together with Capronia villosa but withlow bootstrap value (52 %). The lower part of the tree con-

stitutes of members of the Dothideomycetes or Dothideo-mycetes et Chaetothyriomycetes incertae sedis according toERIKSSON et al. (2004).

Discussion

The two species described here are both easily distinguishedfrom the earlier described Moristroma polysporum (ROMERO

& SAMUELS 1991) by their larger asci (M. polysporum asci40–66 × 12–13 µm), smaller ascospores (M. polysporum asco-spores 3–4 (5) × 0.6–1.2 µm), larger ascostromata and loculi,the presence of numerous pycnidia, their substratum prefe-rences (M. polysporum on Eucalyptus), and known geogra-phic distribution (M. polysporum known from Argentina).

Differences between M. quercinum and M. japonicum aremore subtle, but they differ by the length and width of asci (M.quercinum asci on average shorter and slightly wider), asco-spores (M. quercinum ascospores on average slightly shorterand wider), size of ascostromata (M. quercinum ascostromataon average smaller), shape of pycnidia (M. quercinum pycnidiawith more prominent rostrum), size of conidia (M. quercinumconidia on average slightly larger), and other characters.

Figs 19–34: Moristroma japonicum macromorphology (holotype). – 19-24. Ascostromata. – 19, 21. Vertical sections showingloculi (wo = wood). – 20, 22. Side views (arrows mark positions of ostioles). – 23, 24. From above, with ostioles. – 23. Withattached pycnidium (py). – 25-34. Pycnidia. – 30. With part of the ascostroma indicated. – Del. Stellan Sunhede.

330 NORDÉN, SUNHEDE & LARSSON: Taxonomy and phylogeny of Moristroma (Ascomycetes)

© DGfM 2005

HAWKSWORTH (2001) discussed whether small differen-ces in micromorphology justifies the recognition of separatespecies, and concluded that such characters can be useful. Gi-ven the morphological differences, and the geographic rangeand host differences, we would not hesitate to propose twonew species rather than one, even in the absence of molecu-lar data. The sequence divergence between M. quercinum andM. japonicum further supports the view that they should beregarded as separate species.

The result of the phylogenetic analysis suggests that Mo-ristroma is closer to the Chaetothyriomycetes than to theTeichosporaceae (Dothideomycetes) as proposed by ERIKS-SON et al. (2004), despite the lack of periphyses and the pre-sence of pycnidia in our species. The closest relative in thedata set appear to be C. villosa, although the bootstrap supportis low for this branch. According to UNTEREINER & NAVEAU

(1999), C. villosa is an aberrant species within Capronia,which is supported by our analysis since it did not cluster withthe other Capronia species. Except for Dermatocarpon andVerrucaria representing the Verrucariales, the branches with-in our Chaetothyriomycetes clade is weakly supported, and isnot commented on further.

As in the analysis by LUTZONI et al. (2004), the Chaeto-thyriomycetes clade appear as a sister group to the Eurotio-mycetes, here represented by Penicillium commune, which inturn is sister group of Ostropomycetes (Ostropa barbara). Thelower part of the tree consists of members of the Dothideo-mycetes or “Dothideomycetes et Chaetothyriomycetes incer-

tae sedis” according to ERIKSSON et al. (2004), among themByssothecium of the Teichosporaceae.

The habitat of both M. quercinum and M. japonicum is ex-posed heartwood, which is a very hard and durable substratum.Decorticated oak branches often relatively quickly shed theirsapwood, which is early attacked by various white-rotting ba-sidiomycetes and ascomycetes (Xylariales). However, theheartwood (duramen) may remain for many years in the field,and few species seem to be adapted to degrade this kind ofwood. Thus, our Moristroma species occupy a distinctive ni-che.

Acknowledgements

We wish to thank Erik Ljungstrand for help with the Latin dia-gnoses and Uno Eliasson for valuable comments. Reda Ir‰enai-te provided material from Lithuania. The first author wishes tothank the Sweden-Japan Foundation, the Swedish EnergyAgency, and the foundation of Anna and Gunnar Vidfelt forfinancial support, and Nitaro Maekawa at the Tottori Mycolo-gical Institute for his hospitality during a stay in Japan. We alsothank the reviewer G. Rambold and an anonymous reviewerfor their valuable comments on the manuscript.

ReferencesBARR ME (1987) Prodromus to class Loculoascomycetes. Published

by the author, Amherst, 168 pp.

Figs. 35–43: Moristroma spp. micromorphology. – 35-38. Moristroma quercinum. – 35-37. Asci. – 36. Young ascus. – 37. Asciand pseudoparaphyses (ascus on the left not fully developed). Spores in focus are indicated as clusters of dots in asci. – 38. Spo-res with oil-like droplets. – 39-43. Moristroma japonicum. – 39. Spores, some with oil-like droplets. – 40. Thick-walled cellsof the ascostroma wall. – 41-43. Mature asci. Spores in focus are indicated as clusters of dots in asci. – 35, 36. Nordén 1678. –37, 38. Nordén 1685. – 39-43. Holotype. – Del. Stellan Sunhede.

Mycological Progress 4(4) / 2005 331

© DGfM 2005

Fig. 44: One of two most parsimonious trees, based on sequence data of the internal transcribed spacer and large subunit (rDNA).Other than the Moristroma sequences, the sequences were retrieved from GenBank and were chosen to represent several groupsof dothideomycetes and chaetothyriomycetes. The phylogram was constructed using the exhaustive search option in PAUP 4.0.Dothidea sambuci was used as an outgroup taxon.

ERIKSSON OE, BARAL HO, CURRAH RS, HANSEN K, KURTZMAN CP,RAMBOLD G, LAESSØE T (2004) MYCONET. Outline of Asco-mycota – 2004. http://www.umu.se/myconet/Myconet.html.

GRUBE M, WINKA K (2002) Progress in understanding the evolutionand classification of lichenized ascomycetes. – Mycologist16: 67-76.

HAWKSWORTH DL (2001) The magnitude of fungal diversity: the 1.5million species estimate revisited. – Mycological Research105: 1422-1432.

KÕLJLG U, LARSSON E (1998) Pseudotomentella ochracea sp. nov.,based on morphological and molecular data. – Folia Crypto-gamica Estonica 33: 53-56.

LARSSON E, HALLENBERG N (2001) Species delimitation in the Gloeo-cystidiellum porosum-clavuligerum complex inferred fromcompatibility studies and nuclear rDNA sequence data. – My-cologia 93: 907-914.

LARSSON KH, LARSSON E (1998) A molecular perspective on Cera-ceomyces sublaevis. – Folia Cryptogamica Estonica 33: 71-76.

LUTZONI F, KAUFF F, COX CJ, and a further 41 authors (2004) As-sembling the fungal tree of life: progress, classification, andevolution of subcellular traits. – American Journal of Botany91: 1446-1480.

ROMERO AI, SAMUELS GJ (1991) Studies on xylophilous fungi fromArgentina: VI. Ascomycotina on Eucalyptus viminalis (Myr-taceae). – Sydowia 43: 228-248.

SWOFFORD DL (2000) PAUP*. Phylogenetic Analysis Using Parsi-mony (* and Other Methods). Version 4. Sinauer Associa-tes, Sunderland, MA.

UNTEREINER WA, NAVEAU FA (1999) Molecular systematics of theHerpotrichiellaceae with an assassment of the phylogeneticpositions of Exophiala dermatitidis and Phialophora ameri-cana. – Mycologia 91: 67-83.

332 NORDÉN, SUNHEDE & LARSSON: Taxonomy and phylogeny of Moristroma (Ascomycetes)

VILGALYS R, HESTER M (1990) Rapid Genetic Identification andMapping of Enzymatically Amplified Ribosomal DNA fromseveral Cryptococcus species. – J Bacteriol 172: 4238-4246.

WHITE TJ, BRUNS T, LEE S, TAYLOR JW (1990) Amplification anddirect sequencing of fungal ribosomal RNA genes for phylo-

genetics. Pp 315-322. In: PCR Protocols: A Guide to Methodsand Applications, eds Innis MA, Gelfand DH, Sininsky JJ,White TJ. Academic Press Inc. New York.

Accepted: 30.5.2005

© DGfM 2005