Legend
Key A: Species belonging to Pezizales
Key B: Species belonging to Helotiales
Key C: Species belonging to Hypocreales
Key D: Species belonging to Epibryon
Key E: Species occurring on Polytrichaceae
Key F: Species occurring on Sphagnum
Key G: Species included in this study but not treated in the preceding keys
Key H: Conidial fungi
Key A: Species belonging to Pezizales
KEY TO SPECIES
Copyright
Permission to use and curate this key—curtesy of the editors of Herzogia.
Original key:
Döbbeler, P., Davison, P. G., & Buck, W. R. (2023). Bryophilous ascomycetes of North America–an overview of the recorded species. Herzogia, 36(2), 305-370.
Download updated key as PDF here.
1 Apothecia on thallose, terrestrial liverworts .....................................................................................................................................................................................................................…...................................... 2
1* Apothecia (including modified, perithecia-like ascomata) on leafy liverworts or on mosses ...................................................................................................................................................................................….... 3
2 On Riccia spp.; setae at the apothecial margin; ascospores 14 –16 μm wide, with 1 oil-body; epispore smooth ............................................................................................…………………………………….. Neottiella ricciae
2* On Marchantia polymorpha; setae over the whole excipulum; ascospores 8 –11 μm wide, with 2 oil- bodies; epispore warty ........................................................…………………………………............. Octospora ithacaensis
3 On leafy liverworts, with true or perithecioid apothecia: Filicupula, Octosporella ...................................................................................................................................................................................................….... 4
3* On predominantly acrocarpous mosses, directly on the plants or on soil between them (seemingly ter- restrial), with true often large apothecia: Lamprospora, Neottiella, Octospora (more than 25 species, not treated, see Eckstein 2023)
4 On species of Frullania; ascomata true apothecia, gelatinous, without setae; excipulum of textura porrecta: Filicupula .............................................................................................................................….................... 5
4* On leafy liverworts (including Frullania); ascomata perithecia-like, not gelatinous, setose; excipu- lum of textura epidermoidea: Octosporella ...............................................................................................…............... 6
5 On Frullania inflata; ascospores (in H2O) 25 –34 × 6.5 – 8 μm .................……………………………………………………………………………………………………………....................................…..……………….Filicupula cyanopoda
5* On Frullania kunzei; ascospores (in H2O) 28 – 40 × 7–9 μm ............…………………………………………………………………………………………………………………………………………………………………,,…....... Filicupula sororia
6 Ascomata to 550 μm long and 400 μm wide, setae to 200 μm long; asci 8-spored; ascospores (in H2O) 12–14μm wide, without appendages, at both ends with cap-like thickenings, on jungermannialean liverworts ................................................................................………………………………………………………………………………………………………………………………………………………………………....... Octosporella jungermanniarum
6* Not with this character combination ............................................................................................................................................................................................................................................…......................... 7
7 Ascospores continuously extended at one end into a tail-like, 19–20 × 1μm large appendage; on Frullania asagrayana .................................................................................................................... Octosporella caudifera
7* Ascospores without appendage ............................................................................................................................................................................................................................................................................... 8
8 On Radula complanata; asci 2(3-, 4-)-spored; ascospores 33 –50 μm long, strongly varying in size .. .......................................................................................................................................Octosporella ornithocephala
8* On Frullania spp.; asci 4- or 8-spored; ascospores more homogeneous in size .......................................................................................................................................................................................................…... 9
9 Asci (2-, 3-)4-spored; ascospores in H2O 27–37μm long; on F. appalachiana, F. eboracensis, F. virginica .................................................................................................................…................. Octosporella brevibarbata
9* Asci 8-spored; ascospores in H2O 24 –33 μm long; on F. ericoides ............………………………………………………………………………………………………………………………..………………………………….... Octosporella imitatrix
Key B: Species belonging to Helotiales
Apothecia plane or cupulate, with or without stipe, usually distinctly less than 2mm diam, white (with a lilac tint) to brown, (green in Chlorociboria); paraphyses filiform; asci uni- tunicate, inoperculate, iodine negative or with a blue apical ring in iodine; ascospores (sub) globose, ellipsoidal, (triangular in Pithyella trigona), colorless, nonseptate or 1- or 3-septate; bio- or necrotrophic parasites, rarely saprotrophic.
The helotialian polytrichicolous species Bryoscyphus hyalotectus, Chlorociboria lamel- licola, Durella polytrichina, and Gloeopeziza interlamellaris are treated in Key E (species on Polytrichaceae), the sphagnicolous species Helotium schimperi in Key F (species on Sphagnum).
1 Apothecia cream-white to brown, felty at the outside; asci less than 5μm wide, iodine negative; ascospores (sub)globose or triangular (in surface view), to 4 μm large, nonseptate; on Frullania .........................…………... 2
1* Not with this character combination ...........................................................................................................................................................................................................................................……………............. 3
2 Ascospores (sub)globose, 3–3.5μm diam, warted; not rare on Frullania spp. (one record on Cheilolejeunea clypeata) .........................................................................................................................….. Pithyella chalaudii
2* Ascospores plate-like, in outline triangular, smooth, 3.5 – 4 μm large; few records.........................................................................…………………………………………….........…………………….......……..... Pithyella trigona
3 Apothecia on Marchantia polymorpha, hyaline to white or somewhat lilac, to 2(4) mm diam, margin dentate; ascospores 7–9 × 3 –5 μm .......................................................................................... Pezoloma marchantiae
3* Apothecia not on Marchantia polymorpha, distinctly smaller ......................................................................................................................................................................................................……………………....... 4
4 Apothecia only on the ventral side of the shoots, sessile or shortly stipitate, white; disc to 100μm diam, margin with irregular teeth; asci 4- to 8-spored; ascospores 4 – 6 × 1.5 –2 μm; biotrophic para- site on Bazzania trilobata .......................................................................…………………………………………………………………………………………………………………………………………………………………………….….... Hyphodiscus delitescens
4* Apothecia not restricted to the ventral side of shoots of Bazzania, larger than 200 μm, brown, reddish or white with a pink tint; parasitic on liverworts and/or mosses ...............................................................………..... 5
5 Ascospores 33–40 × 7–8.5μm, 3-septate; apothecia stipitate, to 700μm long; disc 200–450μm diam; necrotrophic, causing yellowish dead host patches ................…...........…...........….......…... Belonioscyphella hypnorum
5* Ascospores less than 22 μm long and less than 4 μm wide, nonseptate ............................................................................................................................................................................................………………......... 6
6 Apothecia pale brown; stipe absent or short; asci 95 –102 × 11–12 μm; ascospores 16 –22 × 3.5 – 4 μm; parasitic on mosses .......................................................................................................... Bryoscyphus turbinatus
6* Apothecia with a pink tint, with a 300 –500 μm long stipe; asci 40 –58 × 5 –7 μm; ascospores 4.5 –7.5 × 2–2.5 μm; necrotrophic parasite on liverworts and mosses ................................................. Roseodiscus subcarneu
Key C: Species belonging to Hypocreales
1 Perithecia dark brown, 110–200 × 85–180μm, setae stiff, dark brown, to 55μm long; asci with 8 one-septate ascospores; ascospores early disintegrating into 2 halves, part-spores triangular in outline, 4 – 4.5 μm diam; on Ptilidium pulcherrimum .......................………………………………………………………………………………………………………………………......………………………......………………………....………………... Trichosphaerella goniospora
1* Perithecia colorless or vividly colored, setae absent or hyaline, rarely yellowish; ascospores not dis- integrating into part-spores .................................................................................................................................. 2
2 Perithecia orange-red, tomentose, without setae, single or as few obligately within the perianths of Frullania preventing the development of the sporophyte; apex of perithecia perforating the perianth wall; small pulvinate, gelatinous conidiomata often present on the outer surface near the perianth base: Periantria ....................................................................................................................................................................…........ 3
2* Not with this character combination ...............................................................................................................................................................................................................................................................……... 4
3 Ascospores subcylindrical, 1-septate, 11.5 –15 × 2.5 –3 μm .......................………………………………………………………………………………………………..……………………………….…………………………. Periantria bellacaptiva
3* Ascospores cylindrical, with 3 –7 transverse septa, 30 – 42 × 2.5 –3 μm .......…………………………………………………………………………………………………………………………..…………..…………………..... Periantria frullaniae
4 Perithecia orange to white (by dense tomentum that often forms a ring-like fringe around the apex of the perithecium); setae colorless, short or to 60 μm long; ostiolar region filled with gelatinous mate- rial; ascospores bacilliform, nonseptate or 1-septate, 8.5 –10.5 × 2–2.5 μm ....…………………………………………………………………………………………………………………………………………………………………………………… Laniatria myxostoma
4* Not with this character combination ...........................................................................................................................................................................................................................................................……...... 5
5 Ascospores consisting of two cells with strongly different shape, size and content, a small ellipsoidal cell with dense cytoplasmic content, and a larger, appendage-like, ellipsoidal to claviform cell with less dense cytoplasmic content; leaf-perforating, on Frullania: Bryotria ................................................................................................................................................................................................................................................ 6
5* Ascospores not consisting of two strongly different cells ........................................................................................................................................................................................................................................... 8
6 Ascospores 5–6μm long, the smaller cell 2–3 × 1μm, the larger cell 3–4 × 2–3μm; perithecia 170 –250 μm long; necrotrophic .................................................................................................................. Bryotria lagodes
6* Ascospores longer than 16 μm ......................................................................................................................................................................................................................................................…………………..... 7
7 Perithecia 90 –140 μm diam; setae very short, inconspicuous; biotrophic ............................................................................................................................................................................................. Bryotria adelpha
7* Perithecia 170 –300 μm long; setae to 30 μm long; necrotrophic ...................................................................................................................................................................................................... Bryotria urophora
8 Perithecia ovoid to pyriform, hyaline, colorless, rarely yellowish, orange or brown; perithecial wall of thick-walled hyphae with small, irregular, ramified and anastomosing lumina of varying width; asci (4-)8-spored; ascospores mostly longer than 10 μm, 1(2)-septate; hyphae superficial, with small lateral, often slightly sinuate appressoria; never leaf-perforating; on liverworts and mosses, biotro- phic parasites: Bryonectria .................................................................................................................................................................................................................................................................................................................................. 9
8* Perithecia (sub)globose, orange or red; perithecial wall of angular cells; asci numerous, 8-spored; ascospores mostly less than 7μm long, variable in shape, 1-septate, septum usually hidden by a cyanophilous central band; cyanophilous reaction of cell walls frequent; hyphae mostly unknown; often leaf-perforating; all on Frullania (apart from B. metzgeriae), bio- or necrotrophic parasites: Bryocentria ....................................................................................................................................................................................................................................................................…………................................................ 14
9 Ascospores 2-septate, 16.5 –19 × 4 –5 μm; asci 4-spored; perithecia hyaline, on Platygyrium repens ...................................................................................................................................................Bryonectria aphanes
9* Ascospores 1-septate, asci 8-spored (in B. callicarpa 4- to 8-spored) .................................................................................................................................................................................…..................................... 10
10 Hosts belonging to Polytrichum spp.; perithecia on the adaxial leaf side arising from the interspaces of the leaf lamellae ............................................................................................................................................ 11
10*Hosts not belonging to Polytrichum ....................................................................................................................................................................................................................................................................... 12
11 Perithecia brown, 190 –250 × 150 –200 μm, surface tomentose; ascospores ovoid, 6 –7.5 μm wide; on Polytrichum juniperinum and P. piliferum; perithecia concentrating in the small region of free-lying lamellae between the inflexed leaf margins ................................................................................................................................................................................................................................................………... Bryonectria phyllogena
11*Perithecia colorless to hyaline, smaller; ascospores ellipsoidal, 3.5–4.5μm wide; on Polytrichum commune and P. formosum; perithecia randomly distributed over the leaf surface ...............…........... Bryonectria cuneifera
12 Perithecia on the ventral leaf margin of Frullania species, colorless to yellow or orange ............................................................................................................................................................................................ 13
Döbbeler et al.: Bryophilous ascomycetes of North America 361 12*Perithecia on and between the leaves of Hylocomium splendens or Platygyrium repens, colorless, hyaline ………........................…...... Bryonectria hylocomii
13 Asci 8 –spored; ascospores 15.5 –18.5 × 4.5 – 6 μm; appressoria 1-septate, 10 –14 μm long; on F. ebo- racensis ........................................................................................................................….. Bryonectria anisopoda
13* Asci 4- to 8-spored; ascospores 10 –14 × 4.5 –5.5 μm; appressoria nonseptate, 5 – 8 μm diam; frequent on various species of Frullania ........................................................….......................….... Bryonectria callicarpa
14 Ascospores consisting of 2 semiglobose cells, in H2O 6 –7 × 3 – 4 μm; perithecia to 130 μm long, leaf- perforating; necrotrophic .............................................................…...........................….... Bryocentria biannulata
14*Ascospores not consisting of 2 semiglobose cells; perithecia mostly larger, between the leaves or leaf-perforating; bio- or necrotrophic ....................................................................................…...........…................. 15
15 Ascospores rod-shaped, central part and both end regions widened resulting in 5 distinguishable segments (CB!), 9 –11 × 1 μm; leaf-perforating; biotrophic ...................….......................….…..... Bryocentria pentamera
15*Not with this character combination ...................................................................................................................................................................................................……………….......................…..………........... 16
16 Perithecia between the leaves, with short, yellowish setae ..........................................................................................................................................……………………………………….......................…..………........... 17
16*Perithecia leaf-perforating, with absent or short, colorless setae ............................................................................................................................................................................................................................. 18
17 Asci 4 –5 μm wide; ascospores 4 –5 × 2–2.5 μm, cyanophilous band ca. 1 μm wide; necrotrophic ..... ................................................…........................................................................................ Bryocentria chrysothrix
17* Asci 5.5 –7 μm wide; ascospores 6 –7 × 3.5 – 4.5 μm, cyanophilous band ca. 2.5 μm wide; biotrophic ...................................................................................…..............................................… Bryocentria pachydesma
18 Ascospores to 2 μm wide ...................................................................................................................................................................................................................................................................................… 19
18*Ascospores wider than 2μm ..........................................................................................................................................................................................................................................................……………...….. 20
19 Ascospores rod- to dumbbell-shaped, 8 –9.5 × 2 μm; biotrophic; on species of Frullania .................. ......................................................................................................….......................…..... Bryocentria brongniartii
19*Ascospores fusiform, 5.5–7.5 × 1.5–2μm; necrotrophic; on Radula complanata (and other liver- worts in Europe) ...........................................................................................................….......... Bryocentria metzgeriae
20 Ascospores rhomboidal, 5 – 6 × 2.5 –3 μm; necrotrophic ............................................................................................................................................................…….....….................…..................... Bryocentria lusor
20*Ascospores narrowly ellipsoidal to fusiform, 5.5–7.5 × 2.5–3μm; biotrophic ….......................................................................................................................................................…............………Bryocentria navicula
Key D: Species belonging to Epibryon
1 Ascospores 1-septate ...........................................................................................................................................................................................................................................……………..............................….... 2
1* Ascospores with more than 1 septum ........................................................................................................................................................................................................................…………….......................…...... 7
2 Ascomata more or less immersed within the tissue of leaves and outermost stem regions, often strongly deformed by pressure of adjacent cells, 40–75μm diam; setae absent; ascospores 9–11 × 1.5 –2 μm, light brown; on Bazzania trilobata ...................................................................................................................................................................................................................................................................... Epibryon intercellulare
2* Not with this character combination ............................................................................................................................................................................................................................…………….......................…... 3
3 Ascomata with a spider-like aspect (by setae curved to the substrate); superficial, on leafy liver- worts .......................................................................................................................................................................... 4
3* Ascomata setose but not spider-like, rarely glabrous; superficial or interlamellar ........................................................................................................................................................................................................ 5
4 Ascomata 30 –55 μm diam; asci 4 – 6 μm wide; ascospores 6.5 –9 × 1.5 –2.5 μm; on Bazzania triloba- ta ......................................................................................................….......................…... Epibryon arachnoideum
4* Ascomata 50 –100 μm diam; asci 7–12 μm wide; ascospores 10 –14 × 3 – 4 μm; on Plagiochila asple- nioides s. lat. .........................................................................................….............................. Epibryon plagiochilae
5 Ascomata superficial, setose; on foliose liverworts and mosses ................................................................................................................................................................................................................................... 6
5* Ascomata superficial, setose, on Sphagnum (E. turfosorum) or immersed between the leaf lamellae of Polytrichaceae, setose or glabrous (E. interlamellare, E. pogonati-urnigeri)
6 Ascomata 75 –100 μm diam; asci 20 –28 × 7–9 μm; ascospores 7–9 × 3 –3.5 μm.............................................................................................…...................................................……………………….....Epibryon casaresii
6* Ascomata 100 –150 μm diam; asci 40 – 66 × 13.5 –18 μm; ascospores 15 –18 × 6.5 – 7.5 μm ..............................................................................................…........................................................... Epibryon bryophilum
7 Ascospores 3-septate ............................................................................................................................................................................................................................................................................................... 8
7* Ascospores with more than 3 septa ........................................................................................................................................................................................................................................................................ 11
8 Ascomata leaf-perforating, setae absent; ascospores 10 –12.5 × 3 –3.5 μm, light brown; on Radula .. .........................................................................…..................................................................Epibryon hypophyllum
8* Ascomata not leaf-perforating, setose; ascospores larger .......................................................................................................................................................................................................................................... 9
9 Setae semicircular, cylindrical with rounded apex, to 40 μm long, with to 6 septa; ascospores 11–14 × 3 – 4 μm; on the tomentum of Dicranum ................................................................…............…...... Epibryon harrisii
9* Setae not strongly curved, acute, septa absent or few; ascospores larger ................................................................................................................................................................................................................... 10
10 Ascomata 55–80μm diam, setae to 25μm long; ascospores 12–15.5 × 3.5–4.5μm, brown; on Ptilidium pulcherrimum (and other liverworts beyond North America) ....…………….......................…..…... Epibryon hepaticicola
10*Ascomata 110–150 × 90–110μm, setae to 60μm long; ascospores 15–19 × 5–7μm, colorless; on Frullania, Porella, Tortella .............................................................…….............................….............. Epibryon muscicola
11 Ascospores transversely septate ............................................................................................................................................................................................................................................................................ 12
11* Ascospores muriform ...................................................................................................................................................................................................................................................……………........................ 13
12 Ascospores with 3.........................–6 septa; ascomata with to 45μm long setae; superficially on the thallus of Metzgeria pubescens ............….................................................................……,........... Epibryon metzgeriae
12*Ascospores mostly with 5 septa; setae absent; leaf perforating on Cheilolejeunea spp. ...................... ..............................................................................................…...........................….................. Epibryon ventrale
13 Ascospores with 5 transverse and few longitudinal septa, ellipsoidal to fusiform, 19–24 × 7–8μm; on Ptilidium pulcherrimum ...................................................................…...................…........... Epibryon intercapillare
13*Ascospores with 7 transverse and few longitudinal septa, narrowly ellipsoidal, 25–34 × 6–8μm; mostly on understory forest liverworts and mosses (e.g., Hylocomium splendens) ..........................…..Epibryon diaphanum
Key E: Species occuring on Polytrichaceae
1 Ascomata obligately within the antheridial cups ........................................................................................................................................................................................................................................................ 2
1* Ascomata occupying other microniches ................................................................................................................................................................................................................................................................... 5
2 Ascomata apothecial, brown; asci unitunicate, iodine negative; ascospores nonseptate or 1-septate, 7.5 –9.5 × 3 μm (Helotiales) ........................................................................................................ Durella polytrichina
2* Ascomata perithecioid, black, forming a pseudostromatic plate-like structure; asci bitunicate; ascospores 1-septate, larger than 23 μm (Pleosporales) Lizonia ..............................................................………………........ 3
3 Asci 8-spored .......................................................................................................................................................................................................................................................................................................... 4
3* Asci 16-spored, 120 –150 × 18 –23 μm; ascospores 23 –29 × 7.5 –9.5 μm; on Oligotrichum aligerum, Polytrichum formosum .......................................................................….............................................. Lizonia baldinii
4 Asci 110 –160 × 19 –23 μm; ascospores 33 – 40 × 9 –12 μm; on Polytrichum commune, P. strictum ... ................................................................................................................................................... Lizonia emperigonia
4* Asci 90 –120 × 15 –20 μm; ascospores 23 –29 × 6 – 8.5 μm; on Polytrichastrum sexangulare ............ ................................................................................................................................................. Lizonia sexangularis
5 Ascomata completely immersed between the leaf lamellae (often distinctly erumpent in Bryonectria cuneifera) .............................................................................................................................................................. 6
5* Ascomata on the leaf lamellae or on the abaxial leaf surface ..........................................................................................................................................................................................................…………………..... 11
6 Ascomata perithecial, colorless; perithecial wall of thick-walled, irregular hyphae with delicate lumi- na; ascospores 1–septate, 10 –12.5 × 3.5 – 4.5 μm ...................................….............................. Bryonectria cuneifera
6* Ascomata perithecioid or lateral ascomatal walls strongly reduced or even absent due to lack of space, resulting in atypical ascomata with asci arranged in a row ....................................................................……......... 7
7 Ascomata perithecioid, globose (circular seen from above or elliptical in outline by lateral compres- sion), brown, to 55 μm diam, with or without setae .................................................................................................. 8
7* Ascomata seen from above fusiform and black or fusiform to linear and colorless, setae absent ................................................................................................................................................................................... 9
8 Setae to 20μm long; hymenial jelly reddish in iodine; ascospores 5.5–7 × 1.5–2μm; unspecific on species of Polytrichaceae ...............................................................................................……..... Epibryon interlamellare
8* Setae absent; inner ostiolar region reddish in iodine (bluish after pretreatment with KOH); ascospores 6.5 –9 × 2– 4 μm; common on Pogonatum urnigerum .................................................... Epibryon pogonati-urnigeri
9 Ascomata black with an irregular clear opening in transmitted light, in surface view 90–160μm long, 18 –55 μm wide; ascus walls reddish in iodine; ascospores 1-septate, 13 –16 × 2–2.5 μm; often associated with a black, fusiform or linear, also immersed pycnidial anamorph (Key H) ................................................................................................................................................................................………….............Potriphila navicularis
9* Ascomata colorless, excipulum extremely reduced, essentially a row of asci with some sterile cells at both ends and at the base; ascus walls not reddish in iodine ................................................................................. 10
10 Ascomata 20–50μm long, 8–14μm wide; asci 15–23 × 7–11μm, iodine reaction none; ascospores 1-septate, 6.5 – 8.5 × 2–2.5 μm ............................................................................................. Dawsomyces subinvisibilis
10*Ascomata 90–180μm long, 18–50μm wide; asci 55–85 × 11.5–18μm, with a blue apical ring in iodine; ascospores nonseptate, 13 –16 × 5.5 –7 μm; not rare on Polytrichastrum sexangulare ....... Gloeopeziza interlamellaris
11 Ascomata mostly on the abaxial leaf surface in the upper leaf region .............................................................................................................................................................................................................…....... 12
11*Ascomata on the leaf lamellae (arising from the interlamellar spaces).......…………………......................................................................................................................................................................................... 13
12 Ascomata 25 –50 μm diam; ascospores1-septate, 9 –11 × 3 – 4 μm; most often on Polytrichum piliferum .................................................................................................................…................... Bryochiton perpusillus
12* Ascomata 60 –110 μm diam; ascospores 2-septate, 11–14 × 3 – 4 μm; on Polytrichastrum sexangulare ............................................................................................................................…....... Bryochiton heliotropicus
13 Ascomata apothecial, green or brown ............................................................................................................................................................................................................................................................…..... 14
13*Ascomata perithecial or perithecioid, brown or black .....................................................................................................................................................................................................................................…..... 15
14 Apothecia green, to 120μm diam, margin dentate; ascospores 5.5–8 × 1.5–2μm; on species with free-lying lamellae not covered by the inflexed margins .................................................…........ Chlorociboria lamellicola
14* Apothecia pale brown, to 220 μm diam, without teeth; ascospores 8 –10.5 × 4 – 4.5 μm; on Polytrichum juniperinum, arising from the interstices of the lamellae where the inflexed leaf margins meet ....................................................................................................................................................................................................................................................................................……….. Bryoscyphus hyalotectus
364 Herzogia 36 (2), 2023
15 Perithecia brown; iodine reaction none; ascospores1-septate; arising from the interstices of the lamel- lae where the inflexed leaf margins meet, on Polytrichum juniperinum, P. piliferum .....…....... Bryonectria phyllogena
15*Ascomata perithecioid, black; hymenial structures including ascus apices reacting with iodine; asco- spores 3-septate, usually single or by twos in the uppermost leaf parts, on Polytrichastrum sexangulare ............................................................................................................................................................................................................................................................................................. Protothelenella polytrichi
Key F: Species occuring on Sphagnum
1 Ascomata apothecial, colorless, without setae ......................................................................................................................................................................................................................................................…... 2
1* Ascomata perithecial or perithecioid, light brown or black, with setae .....................................................................................................................................................................................................…………….... 3
2 Ascus apex with amyloid structure; ascospores 4.5 –5.2 μm wide; hyphae forming cap-like, delicate haustoria at the mucilaginous cells; not lichenized, usually sterile; on Sphagnum squarrosum .....….. Helotium schimperi
2* Whole ascus wall reddish to brown in iodine; ascospores 7.5 –10 μm wide; hyphae associated with Nostoc colonies; on different Sphagnum species .........................................................................…..... Trizodia acrobia
3 Ascomata to 110 μm large, light brown with a dark apical papilla; interascal hyphae absent; hymenial jelly reddish in iodine; ascospores subovoid, 1-septate, 12–14 × 5.5 –7.5 μm ......................………Epibryon turfosorum
3* Ascomatalargerthan400μm,black;paraphysesramified;noreactionofhymenialelementsiniodi- ne; ascospores cylindrical, septate or nonseptate, longer than 30 μm .......................................................................…....... 4
4 Ascospores geniculate in the lower quarter, colorless to brown, nonseptate or with 1–3 septa, 38 –50 × 4.5 – 6 μm .....................................................................................................…........................ Hilberina sphagni
4* Ascospores not geniculate, brown, nonseptate, 34 – 40 × 6 –7.5 μm ............................................................................................................................................................................................ Hilberina sphagnorum
Key G: Species included in this study but not treated in the preceding keys
Apothecia green to dark or blue green, glabrous; ascospores 16 –20 × 9 –11 μm; on jungermannialean liverworts ......................................................................................................................... Mniaecia jungermanniae
1* Ascomata not green ...............................................................................................................................................................................................................................................................................…….......... 2
2 Ascomata brown, to 1mm long, cylindrical, often laterally compressed; ascospores filiform, with many transverse septa; necrotrophic, causing conspicuous yellowish discolored patches within green moss mats, mostly on pleurocarpous mosses .............................................................................................................................................................................................................................................................. Acrospermum adeanum
2* Not with this combination of characters ........................................................................................................................................................................................................…………………………………................... 3
3 Ascomata apothecial, urn-shaped, brown; ascospores 1-septate; hymenial jelly reddish in iodine, gelatinous caps over the asci dark blue; biotrophic parasite on leafy liverworts .........…............... Paruephaedria heimerlii
3* Ascomata perithecioid .............................................................................................................................................................................................................……………………………………..................................... 4
4 Ascomata 360 –540 × 275 – 425 μm; setae 20 –130 μm long; ascospores nonseptate or 1-septate, 32– 39 μm long; iodine reaction negative; on Ptilidium pulcherrimum ..........................................….... Leptomeliola ptilidii
4* Ascomata to 200 μm large; setae absent; ascospores less than 25 μm long, 1- or 3-septate ..................................................................................................................................................................................…...... 5
5 Asci with 16, 24 or about 32 ascospores; hymenial jelly reddish in iodine; on Frullania ....................................................................................................................................................................................……….... 6
5* Asci 8-spored; iodine reaction negative; not on Frullania ............................................................................................................................................................................................................................……........ 9
6 Ascomata leaf-perforating, less than 100 μm diam, globose .................................................................................................................................................................................................................……………........ 7
6* Ascomata not leaf-perforating, more than 100 μm diam, ovoid or urn-shaped ...................................................................................................................................................................................................…….... 8
7 Ascospores 1-septate, 8 –15 μm long ................................................................................................................................................................................................................…………........... Hypobryon florentinum
7* Ascospores 3-septate, 14 –20 μm long ......................................................................................................................................................................................................................…………….... Hypobryon bacillare
8 Ascospores 1-septate, 6 – 8.5 × 2 μm; ascomata urn-shaped ...............................................................................................................................................................................................………. Muellerella rubescens
8* Ascospores 3-septate, 9 –16 × 2–3 μm, ascomata ovoid ......................................................................................................................................................……………………................................. Muellerella frullaniae
9 Ascomata immersed within the thallus of Riccia, 150 –200 μm diam; asci 120 x 12–15 μm; ascospo- res 1-septate, 20 –22 × 8 –10 μm ......................................................................….................... Didymella hepaticarum
Döbbeler et al.: Bryophilous ascomycetes of North America 365
9* Ascomata not immersed within the substrate; ascomata and asci distinctly smaller ............................................................................................................................................................….............................…... 10
10 Ascomata 55 –90 μm diam; asci 30 – 45 μm long; ascospores 18 –22 × 8 –9 μm, 1-septate; on the shoot apices of hypnalean mosses causing a necrosis ................................................................…..... Bryorella acrogena
10* Ascomata to 55 μm large; asci less than 30 μm long; ascospores distinctly smaller, 1- or 3-septate; not on hypnalean mosses; biotrophic, also on old leaves ...............................................................................……... 11
11 Ascospores 1-septate, colorless, (sub)fusiform, on Marsupella .......................................................................................................................................................................………………...... Bryochiton microscopicus
11* Ascospores 3-septate, dark brown, ellipsoidal; on Grimmiaceae, at the uppermost leaf regions and on hyaline hair points ...........................................................................................…............... Bryochiton monascus
Key H: Conidial fungi
1 Conidia enclosed in pycnidia; pycnidia immersed between the leaf lamellae, in surface view fusiform to linear, black, 80 –160 × 8 –25 μm; ostiole in transmitted light as a clear spot; conidia subcylindri- cal, colorless, nonseptate, 9 –12 × 2–3 μm; mainly on Polytrichastrum alpinum, often associated with the teleomorph (Key E) ...............................................................................................................…................ Potriphila navicularis
1* Conidia not within pycnidia; conidiomata absent or present .......................................................................................................................................................................................................……………................ 2
2 Conidiomata absent, conidiophores arising from the leaf axils of a living moss, with single, brown, muriform conidia ..................................................................………………………..................... Stemphylium botryosum
2* Conidiomata present, sporodochial or cushion-shaped ......................................................................................................................................................................................................................................….... 3
3 Conidiomata on the lower perianth, gray, gelatinous; conidia globose, colorless, nonseptate, 1–2 μm diam; on Frullania spp., often associated with the teleomorph (Key C) ..................Periantria bellacaptiva, P. frullaniae
3* Conidiomata on and between the leaves, brown or black, not gelatinous; conidia not globose, colo- red, much larger than 2 μm, septate; not on Frullania .................................................................................………..... 4
4 Conidiomata brown, 20–70μm diam; conidia 2-septate, 7.5–9 × 3–4μm; on Nowellia and Ptilidium ................................................................................................................................ Pseudomicrodochium bryophilum
4* Conidiomata black, 60 –200 μm diam; conidia 1-septate, 14 –18 μm long, distal cell 10 –14 μm diam, proximal cell 4.5 –7 μm diam; on Plagiochila asplenioides s. lat. ...............................…............ Epicoccum plagiochilae