Checklist of lichens of Wisconsin (USA)
Version 31 December 2018
- Acarospora americana H. Magn. - Thomson (2003: 26), Thomson (2003: 26 as Acarospora cinereoalba)
- Acarospora elevata H. Magn. - Howard (1950: as Acarospora washingtonensis), Douglas (1974: 584 as Acarospora washingtonensis)
- Acarospora fuscata (Nyl.) Arnold - Howard (1950: ), Douglas (1974: 584), Thomson (1997: 24), Thomson (2003: 26)
- Acarospora moenium (Vain.) Räsänen - Lay (2004: as Aspicilia moenium)
- Acarospora schleicheri (Ach.) A. Massal. - Thomson (1997: 33), Bennett (2006: )
- Acarospora veronensis A. Massal. - Thomson (1997: 35), Thomson (2003: 26)
- Acrocordia cavata (Ach.) R. C. Harris - Thomson (2003: 27)
- Acrocordia conoidea (Fr.) Körb. - Thomson (2003: 27)
- Acrocordia megalospora (Fink) R. C. Harris - Thomson (2003: 27)
- Adelolecia kolaensis (Nyl.) Thomson (1997: 338 as Lecidea conferenda), Hertel & Rambold - Bennett (2006: )
- Agonimia opuntiella (Buschardt & Poelt) Vezda - Bennett (2006: )
- Ahtiana aurescens (Tuck.) A. Thell & Randlane - Thomson (2003: 28), Bennett & Wetmore (2004: 172 Historical Occurrences)
- Alyxoria varia Pers. - Thomson (2003: 156 as Opegrapha varia)
- Amandinea dakotensis (H. Magn.) P. May & Sheard - Thomson (2003: 28)
- Amandinea milliaria (Tuck.) P. May & Sheard - Thomson (2003: 29)
- Amandinea polyspora (Willey in Tuck.) E. Lay & P. May - Thomson (1997: 137 as Buellia polyspora), Thomson (2003: 29), Lay (2004: 17)
- Amandinea punctata (Hoffm.) Coppins & Scheid. - Thomson (1997: 138 as Buellia punctata), Thomson (2003: 29), Thomson (2003: 49 as Buellia stigmatea), Lay (2004: 17)
- Anaptychia crinalis (Schaer.) Vezda - Thomson (1984: 40 as Anaptychia kaspica), Thomson (2003: 30 erroneously as Anaptychia setifera), Bennett & Wetmore (2004: 172 as Anaptychia setifera Critically Imperiled)
- Anaptychia palmulata (Michx.) Vain. - Thomson (2003: 30)
- Anisomeridium biforme (Borrer) R. C. Harris - Thomson (2003: 30)
- Anisomeridium leucochlorum (Müll. Arg.) R. C. Harris - Thomson (2003: 30)
- Anisomeridium polypori (Ellis & Everh.) M. E. Barr - Thomson (2003: 30)
- Anzia colpodes (Ach.) Stizenb. - Thomson (2003: 30), Bennett & Wetmore (2004: 172 Historical Occurrences)
- Arthonia anglica Coppins - Lendemer et al. (2009: )
- Arthonia apatetica (A. Massal.) Th. Fr. - Lay (2004: )
- Arthonia atra (Pers.) A. Schneid. - Thomson (2003: 155 as Opegrapha atra)
- Arthonia byssacea (Weigel) Almq. - Thomson (2003: 32)
- Arthonia caudata Willey - Lay (2004: ) Fungus
- Arthonia didyma Körb. - Thomson (2003: 33)
- Arthonia diffusa Nyl. - Thomson (2003: 35 as Arthonia willeyi) fide Lendemer 2004
- Arthonia diffusella Fink ex J. Hedrick - Bennett (2006)
- Arthonia dispersa (Schrad.) Dufour - Brodo (1967: 211), Thomson (2003: 33)
- Arthonia fuliginosa (Schaer.) Flotow - Thomson (2003: 33)
- Arthonia glebosa Tuck. - Bennett (2006: )
- Arthonia granosa de Lesd. - Brodo (1967: 211), Thomson (2003: 33)
- Arthonia helvola (Nyl.) Nyl. - Lay (2004: )
- Arthonia patellulata Nyl. - Brodo (1967: 211), Thomson (1997: 47), Thomson (2003: 34), Lay (2004: 17)
- Arthonia polymorpha Ach. - Thomson (2003: 34)
- Arthonia punctiformis Ach. - Brodo (1967: 211), Thomson (2003: 34)
- Arthonia radiata (Pers.) Ach. - Brodo (1967: 211), Thomson (2003: 34)
- Arthonia rubella (Fée) Nyl. - Bennett (2006: )
- Arthonia rupicola Fink - Thomson (2003: 34)
- Arthonia spadicea Leight. - Thomson (2003: 35)
- Arthothelium hallii (Tuck.) Zahlbr. - Thomson (2003: 35)
- Arthothelium spectabile A. Massal. - Thomson (2003: 35)
- Arthrosporum populorum A. Massal. - Thomson (2003: 41 as Bacidia populorum), Lay (2004: 17)
- Aspicilia cinerea (L.) Körb. - Thomson (1997: 68), Thomson (2003: 36)
- Aspicilia laevata (Ach.) Arnold - Thomson (2003: 37)
- Aspicilia limitata (H. Magn.) J. W. Thomson - Thomson (2003: 37)
- Aspicilia verrucigera Hue - Lay (2004: )
- Athallia holocarpa (Hoffm.) Arup, Frödén & Søchting - Thomson (1997: 164 as Caloplaca holocarpa), Thomson (2003: 56 as Caloplaca holocarpa), Lay (2004: 18 as Caloplaca holocarpa)
- Athallia vitellinula (Nyl.) Arup, Frödén & Søchting - Thomson (2003: 58 as Caloplaca vitellinula)
- Bacidia bagliettoana (A. Massal. & De Not.) Jatta - Brodo (1967: 212 as Bacidia muscorum), Thomson (1997: 99), Thomson (2003: 39)
- Bacidia circumspecta (Norrl. & Nyl.) Malme - Thomson (1997: 110 as Bacidia sphaeroides), Lay (2004: 18)
- Bacidia coprodes (Körb.) Lettau - Brodo (1967: 212 as Bacidia pammellii), Brodo (1967: 212 erroneously as Bacidia trachona), Thomson (1997: 112 as Bacidia trachona), Thomson (2003: 40 as Bacidia granosa)
- Bacidia diffracta S. Ekman - Thomson (2003: 40)
- Bacidia laurocerasi (Delise ex Duby) Zahlbr. subsp. laurocerasi - Thomson (2003: 40)
- Bacidia polychroa (Th. Fr.) Körb. - Thomson (2003: 41)
- Bacidia rubella (Hoffm.) A. Massal. - Thomson (1997: 107), Thomson (2003: 41)
- Bacidia schweinitzii (Fr. ex Tuck.) A. Schneid. - Thomson (2003: 41)
- Bacidia subincompta (Nyl.) Arnold - Thomson (2003: 42)
- Bacidia suffusa (Fr.) A. Schneid. - Thomson (2003: 42)
- Bacidina egenuloidea (Fink) S. Ekman - Thomson (2003: 43)
- Bacidina inundata (Fr.) Vezda - Brodo (1967: 212), Thomson (2003: 43)
- Baeomyces rufus (Hudson) Rebent. - Thomson (2003: 43)
- Bagliettoa calciseda DC. - Thomson (2003: 242 as Verrucaria calciseda)
- Biatora helvola Körb. ex Hellbom - Thomson (1997:349 as Lecidea helvola), Thomson (2003: 45)
- Biatora longispora (Degel.) Lendemer & Printzen - Lay (2004: )
- Biatora toensbergii Holien & Printzen - Lay (2004: )
- Biatora vernalis (L.) Fr. - Thomson (2003: 45)
- Bilimbia microcarpa (Th. Fr.) Th. Fr. - Thomson (1997: 105 as Bacidia microcarpa), Thomson (2003: 149 as Mycobilimbia microcarpa)
- Bilimbia sabuletorum (Schreb.) Arnold - Brodo (1967: 212 as Bacidia sabuletorum), Thomson (1997: 422 as Mycobilimbia sabuletorum), Thomson (2003: 149 as Mycobilimbia sabuletorum)
- Blastenia ferruginea (Hudson) Th. Fr. - Thomson (2003: 55 as Caloplaca ferruginea)
- Bryobilimbia ahlesii (Körber) Fryday, Printzen & S. Ekman - Bennett (2006: as Lecidea delincta)
- Bryobilimbia hypnorum Lib. - Thomson (1997: 351 as Lecidea hypnorum), Thomson (2003: 149 as Mycobilimbia hypnorum)
- Bryoria capillaris (Ach.) Brodo & D. Hawksw. - Thomson (2003: 46), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Bryoria fremontii (Tuck.) Brodo & D. Hawksw. - Howard (1950: as Alectoria fremontii), Douglas (1974: 584 as Alectoria fremontii)
- Bryoria furcellata (Fr.) Brodo & D. Hawksw. - Thomson (2003: 46)
- Bryoria fuscescens (Gyeln.) Brodo & D. Hawksw. - Bennett (2006: )
- Bryoria nadvornikiana (Gyeln.) Brodo & D. Hawksw. - Thomson (2003: 46), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Bryoria trichodes (Michx.) Brodo & D. Hawksw. subsp. trichodes - Thomson (1984: 68), Thomson (2003: 46)
- Buellia arnoldii Servít & Nádv. - Thomson (2003: 48)
- Buellia badia (Fr.) A. Massal. - Thomson (2003: ), Thomson (2003: 50 as Buellia turgescens)
- Buellia disciformis (Fr.) Mudd - Thomson (1997: 129), Thomson (2003: 48)
- Buellia erubescens Arnold - Thomson (1997: 131), Thomson (2003: 48), Thomson (2003: 50 as Buellia stillingiana)
- Buellia maculata Bungartz - Thomson (2003: )
- Buellia mamillana (Tuck.) W. A. Weber - Thomson (2003: 49)
- Buellia nigra (Fink) Sheard - Bennett (2006: )
- Buellia schaereri De Not. - Thomson (2003: 48), Lay (2004: 18)
- Buellia spuria (Schaer.) Anzi - Thomson (1997: 139), Bennett (2006: )
- Buellia vilis Th. Fr. - Thomson (1997: 141), Thomson (2003: 50)
- Caeruleum immersum (Fink) K. Knudsen & B. Abbott - Thomson (2003: 26 as Acarospora immersa), Thomson (2003: as Myriospora immersa)
- Calicium abietinum Pers. - Thomson (1997: 143), Thomson (2003: 50)
- Calicium glaucellum Ach. - Thomson (2003: 51)
- Calicium parvum Tibell - Thomson (2003: 52)
- Calicium salicinum Pers. - Thomson (2003: 52)
- Calicium trabinellum - Thomson (1997: 145), Thomson (2003: 52)
- Caloplaca ahtii Søchting - Bennett (2006: )
- Caloplaca atroalba (Tuck.) Zahlbr. - Thomson (2003: 54)
- Caloplaca brunneola Wetmore - Thomson (2003: 54)
- Caloplaca cerina (Ehrh. ex Hedw.) Th. Fr. - Thomson (1997: 154), Thomson (2003: 54), Lay (2004: 18)
- Caloplaca fraudans (Th. Fr.) Oliv. - Thomson (1997: 162)
- Caloplaca microphyllina (Tuck.) Hasse - Thomson (2003: 57)
- Caloplaca parvula Wetmore - Bennett (2006: )
- Caloplaca pollinii (A. Massal.) Jatta - Thomson (2003: 57)
- Caloplaca saxicola (Hoffm.) Nordin - Thomson (1997: 169), Thomson (2003: 57)
- Caloplaca sideritis (Tuck.) Zahlbr. - Thomson (2003: 58)
- Caloplaca ulmorum (Fink) Fink - Thomson (2003: 58)
- Candelaria concolor (Dickson) Stein - Thomson (2003: 59), Lay (2004: 18)
- Candelaria fibrosa (Fr.) Müll. Arg. - Thomson (2003: 59)
- Candelariella aurella (Hoffm.) Zahlbr. - Thomson (1997: 182), Thomson (2003: 60)
- Candelariella coralliza (Nyl.) H. Magn. - Thomson (1997: 183), Thomson (2003: 60)
- Candelariella efflorescens R. C. Harris & W. R. Buck - Thomson (1997: 185), Thomson (2003: 60)
- Candelariella reflexa (Nyl.) Lettau - Lay (2004: )
- Candelariella vitellina (Hoffm.) Müll. Arg. - Thomson (1997: 189), Thomson (2003: 61), Lay (2004: 18)
- Candelariella xanthostigma (Ach.) Lettau - Thomson (1997: 190), Thomson (2003: 61)
- Canoparmelia texana (Tuck.) Elix & Hale - Thomson (2003: 62)
- Carbonicola anthracophila (Nyl.) P. James & Gotth. Schneider - Thomson (2003: 109 as Hypocenomyce anthracophila)
- Catapyrenium cinereum (Pers.) Körb. - Thomson (1984: 210 as Dermatocarpon cinereum)
- Catillaria chalybeia (Borrer) A. Massal. - Thomson (1997: 196), Thomson (2003: 64)
- Catillaria lenticularis (Ach.) Th. Fr. - Bennett (2006: )
- Catillaria nigroclavata (Nyl.) Schuler - Lay (2004: )
- Catinaria atropurpurea (Schaer.) Vezda & Poelt - Thomson (2003: 64 as Catillaria atropurpurea)
- Cetraria arenaria Kärnefelt - Thomson (2003: 65), Bennett & Wetmore (2004: 172 Historical Occurrences)
- Cetraria ericetorum Opiz subsp. ericetorum - Thomson (1984: 79), Bennett (2006: )
- Cetrelia cetrarioides (Del.) W. L. Culb. & C. F. Culb. - Thomson (2003: 66)
- Cetrelia chicitae (W. L. Culb.) W. L. Culb. & C. F. Culb. - Thomson (2003: 66)
- Cetrelia olivetorum (Nyl.) W. L. Culb. & C. F. Culb. - Thomson (2003: 66)
- Chaenotheca brunneola (Ach.) Müll. Arg. - Thomson (2003: 67)
- Chaenotheca chrysocephala (Turner ex Ach.) Th. Fr. - Thomson (1997: 205), Thomson (2003: 67)
- Chaenotheca ferruginea (Turner ex Sm.) Mig. - Thomson (2003: 68)
- Chaenotheca furfuracea (L.) Tibell - Thomson (1997: 210 as Coniocybe furfuracea), Thomson (2003: 68)
- Chaenotheca gracillima (Vain.) Tibell - Lay (2004: )
- Chaenotheca laevigata Nádv. - Thomson (2003: 68)
- Chaenotheca phaeocephala (Turner) Th. Fr. - Thomson (1997: 206), Thomson (2003: 68), Bennett (2006: )
- Chaenotheca stemonea (Ach.) Müll. Arg. - Thomson (2003: 68)
- Chaenotheca trichialis (Ach.) Th. Fr. - Thomson (2003: 69)
- Chaenotheca xyloxena Nádv. - Thomson (2003: 69)
- Chrismofulvea dialyta (Nyl.) Marbach - Thomson (2003: 48 as Buellia dialyta)
- Chrysothrix caesia (Flot.) Ertz & Tehler - Brodo (1967: 211 as Arthonia caesia), Thomson (2003: 30 as Arthonia caesia), Thomson (2003: 33 as Arthonia lecideella), Lay (2004: 17 as Arthonia caesia)
- Chrysothrix candelaris (L.) J. R. Laundon - Lay (2004: )
- Circinaria caesiocinerea (Nyl. ex Malbr.) A. Nordin, S. Savić & Tibell - Thomson (1997: 65 as Aspicilia caesiocinerea), Thomson (2003: 36 as Aspicilia caesiocinerea)
- Circinaria contorta (Hoffm.) A. Nordin, S. Savić & Tibell - Thomson (2003: 37 as Aspicilia contorta)
- Cladonia acuminata (Ach.) Norrlin - Thomson (1984: 152 as Cladonia norrlinii), Thomson (2003: 76), Bennett & Wetmore (2004: 173 Extinct)
- Cladonia amaurocraea (Flörke) Schaer. - Thomson (1984: 107), Thomson (2003: 76)
- Cladonia apodocarpa Robbins - Thomson (2003: 76)
- Cladonia arbuscula (Wallr.) Flot. - Thomson (2003: 71 as Cladina arbuscula), Bennett & Wetmore (2004: 172 Historical Occurrences)
- Cladonia borealis S. Stenroos - Bennett (2006: )
- Cladonia botrytes (Hag.) Willd. - Thomson (1984: 114), Thomson (2003: 77)
- Cladonia caespiticia (Pers.) Flörke - Thomson (2003: 77), Thomson (2003: 77)
- Cladonia cariosa (Ach.) Spreng. - Brodo (1967: 212), Thomson (1984: 116), Thomson (2003: 77)
- Cladonia carneola (Fr.) Fr. - Lay (2004: )
- Cladonia cenotea (Ach.) Schaer. - Thomson (1984: 118), Thomson (2003: 78)
- Cladonia cervicornis (Hoffm.) Ahti - Thomson (2003: as )
- Cladonia chlorophaea ( Flörke ex. Sommerf.) Spreng. - Brodo (1967: 212), Thomson (1984: 119), Thomson (2003: 78)
- Cladonia coccifera (L.) Willd. - Thomson (1984: 121)
- Cladonia coniocraea (Flörke) Spreng. - Brodo (1967: 212), Thomson (1984: 122), Thomson (2003: 78)
- Cladonia crispata (Ach.) Flot. var. crispata - Thomson (1984: 125), Thomson (2003: 79)
- Cladonia cristatella Tuck. - Brodo (1967: 212), Thomson (2003: 80)
- Cladonia cryptochlorophaea Asah. - Thomson (1984: 126), Thomson (2003: 80)
- Cladonia cylindrica (A. Evans) A. Evans - Thomson (2003: 80)
- Cladonia decorticata (Flörke) Speng. - Brodo (1967: 212), Thomson (1984: 128), Thomson (2003: 80), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Cladonia deformis (L.) Hoffm. - Thomson (1984: 129), Thomson (2003: 81)
- Cladonia didyma (Fée) Vain. - Thomson (2003: 81)
- Cladonia digitata (L.) Hoffm. - Thomson (1984: 131), Thomson (2003: 81)
- Cladonia dimorphoclada Robbins - Thomson (2003: 81)
- Cladonia farinacea (Vain.) A. Evans - Thomson (2003: 82)
- Cladonia fimbriata (L.) Fr. - Thomson (1984: 133), Thomson (1984: 144 as Cladonia major), Thomson (2003: 82)
- Cladonia floerkeana (Fr.) Flörke - Thomson (1984: 134), Thomson (2003: 82)
- Cladonia furcata (Hudson) Schrad. - Brodo (1967: 212), Thomson (2003: 83)
- Cladonia gracilis (L.) Willd. subsp. turbinata (Ach.) Ahti - Thomson (1984: 136), Thomson (2003: 83)
- Cladonia gracilis (L.) Willd. subsp. gracilis - Thomson (1984: 137)
- Cladonia grayi Merrl. - Thomson (1984: 139), Thomson (2003: 83)
- Cladonia humilis (With.) J. R. Laundon - Thomson (2003: )
- Cladonia incrassata Flörke - Thomson (2003: 84), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Cladonia macilenta var. bacillaris (Genth) Schaerer - Thomson (1984: 111 as Cladonia bacillaris), Thomson (2003: 77 as Cladonia bacillaris), Lay (2004: 18) The name Cladonia bacillaris is available
- Cladonia macilenta Hoffm. var. macilenta - Thomson (2003: 84)
- Cladonia merochlorophaea Asah. - Thomson (1984: 143), Thomson (2003: 84)
- Cladonia mitis Sandst. - Thomson (1984: 148), Thomson (2003: 71 as Cladina mitis)
- Cladonia multiformis Merr. - Thomson (1984: 149), Thomson (2003: 84)
- Cladonia parasitica (Hoffm.) Hoffm. - Thomson (2003: 85), Lay (2004: 18)
- Cladonia petrophila R. C. Harris - Harris (1992: 329 First record), Thomson (2003: 85)
- Cladonia peziziformis (With.) J. R. Laundon - Brodo (1967: 212 as Cladonia capitata), Thomson (2003: 85)
- Cladonia phyllophora Hoffm. - Thomson (2003: 86)
- Cladonia pleurota (Flörke) Schaer. - Thomson (1984: 154), Thomson (2003: 86)
- Cladonia pocillum (Ach.) O. Rich. - Thomson (1984: 156), Thomson (2003: 86)
- Cladonia pyxidata (L.) Hoffm. - Brodo (1967: 212), Thomson (1984: 158), Thomson (2003: 87)
- Cladonia ramulosa (With.) J. R. Laundon - Thomson (1984: 109 as Cladonia anomaea), Thomson (2003: 87)
- Cladonia rangiferina (L.) F. H. Wigg. - Thomson (1984: 159), Thomson (2003: 72 as Cladina rangiferina)
- Cladonia rei Schaerer - Brodo (1967: 212 as Cladonia nemoxyna), Thomson (2003: 87)
- Cladonia robbinsii A. Evans - Thomson (2003: 88)
- Cladonia scabriuscula (Del. in Duby) Nyl. - Thomson (1984: 160), Thomson (2003: 88)
- Cladonia squamosa (Scop.) Hoffm. - Thomson (1984: 161), Thomson (2003: 88)
- Cladonia stellaris (Opiz) Pouzar & Vezda - Thomson (1984: 163), Thomson (2003: 72 as Cladina stellaris)
- Cladonia strepsilis (Ach.) Grognot - Thomson (2003: 89)
- Cladonia stygia (Fr.) Ahti - Thomson (2003: 72 as Cladina stygia), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Cladonia subcariosa Nyl. - Thomson (2003: ), Thomson (2003: 86 as Cladonia polycarpoides), Thomson (2003: 88 as Cladonia sobolescens)
- Cladonia subtenuis (Abb.) Hale & Culb. - Thomson (2003: 72 as Cladina subtenuis)
- Cladonia subulata (L.) F. H. Wigg. - Thomson (2003: 89)
- Cladonia sulphurina (Michx.) Fr. - Thomson (2003: 89), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Cladonia symphycarpia (Ach.) Fr. - Thomson (1984: 170), Bennett (2006: )
- Cladonia turgida Ehrh. ex Hoffm. - Thomson (1984: 172), Thomson (2003: 90)
- Cladonia uncialis (L.) Weber ex F. H. Wigg. - Thomson (1984: 173), Thomson (2003: 90)
- Cladonia verticillata (Hoffm.) Schaer. - Thomson (1984: 174), Thomson (2003: 90)
- Clavascidium lacinulatum (Ach.) M. Prieto var. lacinulatum - Thomson (2003: 63 as Catapyrenium lacinulatum)
- Clavascidium umbrinum (Breuss) Breuss - Thomson (2003: 64 as Catapyrenium umbrinum)
- Coenogonium luteum (Dicks.) Kalb & Lücking - Thomson (2003: 98 as Dimerella lutea)
- Coenogonium pineti (Schrad. ex Ach.) Lücking & Lumbsch - Thomson (2003: 98 as Dimerella pineti)
- Collema flaccidum (Ach.) Ach. - Thomson (2003: 92)
- Collema furfuraceum (Schaer.) Du Rietz - Thomson (1984: 187), Thomson (2003: 92)
- Collema nigrescens (Huds.) DC. - Thomson (2003: 93)
- Collema pustulatum Ach. - Thomson (2003: 93)
- Collema subflaccidum Degel. - Thomson (2003: 94)
- Cresponea chloroconia (Tuck.) Egea & Torrente - Thomson (2003: 95)
- Cyphelium lucidum (Th. Fr.) Th. Fr. - Thomson (2003: 96)
- Cyphelium tigillare (Ach.) Ach. - Thomson (1997: 214), Thomson (2003: 96)
- Cystocoleus ebeneus (Dillwyn) Thwaites - Thomson (2003: 96)
- Dermatocarpon americanum Vain. - Heidmarsson (2003: 466)
- Dermatocarpon luridum (With.) J. R. Laundon - Thomson (1984: 213 as Dermatocarpon fluviatile), Thomson (2003: 97)
- Dermatocarpon miniatum (L.) Mann. - Brodo (1967: 211), Thomson (1984: 219), Thomson (2003: 97)
- Dimelaena oreina (Ach.) Norman - Thomson (1997: 216), Thomson (2003: 98)
- Diploschistes muscorum (Scop.) R. Sant. - Thomson (1997: 218), Thomson (2003: 99)
- Diploschistes scruposus (Schreb.) Norman - Thomson (1997: 218), Thomson (2003: 99)
- Diplotomma alboatrum (Hoffm.) Flot. - Thomson (1997: 127 as Buellia alboatra), Thomson (2003: 100)
- Dirinaria frostii (Tuck.) Hale & W. L. Culb. - Thomson (2003: 100), Bennett & Wetmore (2004: 172 Historical Occurrences)
- Distopyrenis americana Aptroot - Lay (2004: )
- Enchylium bachmanianum (Fink) Otálora, P. M. Jørg. & Wedin - Thomson (2003: 92 as Collema bachmanianum)
- Enchylium conglomeratum (Hoffm.) Otálora, P. M. Jørg. & Wedin - Thomson (2003: 92 as Collema conglomeratum)
- Enchylium polycarpon (Hoffm.) Otálora, P. M. Jørg. & Wedin - Thomson (1984: Collema polycarpon), Thomson (1997: 190 as Collema polycarpon), Thomson (2003: 93 as Collema polycarpon), Bennett & Wetmore (2004: 172 as Collema polycarpon Historical Occurrences)
- Enchylium tenax (Sw.) Gray - Thomson (1984: as Collema tenax), Thomson (1997: 192 as Collema tenax), Thomson (2003: 94 as Collema tenax)
- Endocarpon diffractellum (Nyl.) Gueidan & Cl. Roux - Thomson (2003: 220 as Staurothele diffractella)
- Endocarpon pusillum Hedwig - Brodo (1967: 211), Thomson (2003: 101)
- Eopyrenula intermedia Coppins ex Aptroot - Thomson (2003: 101)
- Ephebe lanata (L.) Vain. - Thomson (1984: 225), Thomson (2003: 102), Bennett & Wetmore (2004: 173 Extinct)
- Epigloea soleiformis Döbbeler - Lay (2004: )
- Evernia mesomorpha Nyl. - Thomson (1984: 229), Thomson (2003: 102), Lay (2004: 18)
- Evernia prunastri (L.) Ach. - Thomson (2003: 103), Bennett & Wetmore (2004: 172 Historical Occurrences)
- Flavoparmelia baltimorensis (Gyelnik & Fóriss) Hale - Thomson (2003: 103)
- Flavoparmelia caperata (L.) Hale - Thomson (2003: 103)
- Flavoplaca citrina (Hoffm.) Arup, Frödén & Søchting - Thomson (1997: 155 as Caloplaca citrina), Thomson (2003: 55 as Caloplaca citrina)
- Flavopunctelia flaventior (Stirt.) Hale - Thomson (2003: 104)
- Flavopunctelia soredica (Nyl.) Hale - Thomson (2003: 104)
- Fuscidea pusilla Tønsberg - Lay (2004: )
- Fuscopannaria ahlneri (P. M. Jørg) P. M. Jørg. - Thomson (2003: )
- Fuscopannaria leucosticta (Tuck.) P. M. Jørg. - Bennett & Wetmore (2004: ), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Fuscopannaria praetermissa (Nyl.) P. M. Jørg. - Bennett (2006: )
- Gassicurtia vernicoma (Tuck.) Marbach - Thomson (2003: 50 as Buellia vernicoma)
- Graphis intricata Fée - Thomson (2003: 105)
- Graphis scripta (L.) Ach. - Thomson (2003: 105)
- Gyalecta fagicola (Hepp ex Arnold) Zwackh - Thomson (2003: 156 as Pachyphiale fagicola)
- Gyalecta truncigena (Ach.) Hepp - Thomson (2003: 106)
- Gyalolechia flavorubescens (Hudson) Søchting, Frödén & Arup - Thomson (2003: 56 as Caloplaca flavorubescens)
- Gyalolechia flavovirescens (Wulf.) Søchting, Frödén & Arup - Thomson (1997: 161 as Caloplaca flavovirescens), Thomson (2003: 56 as Caloplaca flavovirescens)
- Gyalolechia xanthostigmoidea (Räsänen) Søchting, Frödén & Arup - Thomson (1997: 158 as Caloplaca discolor), Thomson (2003: 55 as Caloplaca discolor)
- Heppia lutosa (Ach.) Nyl. - Thomson (1997: 244), Thomson (2003: 106), Bennett & Wetmore (2004: 172 Imperiled)
- Heterodermia galactophylla (Tuck.) W. L. Culb. - Thomson (2003: 107)
- Heterodermia hypoleuca (Muhl.) Trevisan - Thomson (2003: 107)
- Heterodermia pseudospeciosa (Kurok.) W. L. Culb. - Thomson (2003: 107)
- Heterodermia speciosa (Wulfen) Trevisan - Thomson (2003: 108)
- Hyperphyscia adglutinata (Flörke) H. Mayrh. & Poelt - Thomson (2003: 108)
- Hyperphyscia syncolla (Tuck. ex Nyl.) Kalb - Thomson (2003: 108)
- Hypocenomyce scalaris (Ach. ex Lilj.) M. Choisy - Thomson (1997: 248), Thomson (2003: 110)
- Hypogymnia physodes (L.) Nyl. - Thomson (1984: 241), Thomson (2003: 110)
- Hypogymnia tubulosa (Schaer.) Hav. - Thomson (2003: 111), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Hypotrachyna revoluta (Flörke) Hale - Lay (2004: )
- Icmadophila ericetorum (L.) Zahlbr. - Thomson (1997: 249), Thomson (2003: 111)
- Imshaugia aleurites (Ach.) S. F. Meyer - Thomson (1984: 321 as Parmeliopsis aleurites), Thomson (2003: 112)
- Imshaugia placorodia (Ach.) S. F. Meyer - Thomson (2003: 112)
- Ionaspis lacustris (With.) Lutzoni - Bennett (2006: )
- Lasallia papulosa (Ach.) Llano - Thomson (1984: 245), Thomson (2003: 113)
- Lathagrium fuscovirens (With.) Otálora, P.M. Jørg. & Wedin - Thomson (1984: 192 as Collema tuniforme), Thomson (2003: 93 as Collema fuscovirens)
- Lathagrium undulatum (Laurer ex Flot.) Otálora, P. M. Jørg. & Wedin - Thomson (2003: 94 as Collema undulatum)
- Lecania cyrtella (Ach.) Th. Fr. - Lay (2004: )
- Lecania dubitans (Nyl.) A. L. Sm. - Thomson (2003: 114)
- Lecania erysibe (Ach.) Mudd - Thomson (1997: 258), Thomson (2003: 114)
- Lecania fuscella (Schaer.) A. Massal. - Thomson (2003: 114)
- Lecania naegelii (Hepp) Diederich & van den Boom - Thomson (2003: 40 as Bacidia naegelii), Thomson (2003: )
- Lecania nylanderiana A. Massal. - Thomson (2003: 114)
- Lecanora albella (Pers.) Ach. var. albella - Thomson (2003: 117)
- Lecanora albellula (Nyl.) Th. Fr. - Thomson (1997: 299 as Lecanora piniperda), Thomson (2003: 118)
- Lecanora allophana (Ach.) Nyl. - Thomson (1997: 266), Thomson (2003: 118)
- Lecanora argentata (Ach.) Malme - Thomson (2003: 118)
- Lecanora argentea Oxner & Volkova - Thomson (1997: 281 as Lecanora fuliginosa), Bennett (2006: )
- Lecanora cadubriae (A. Massal.) Hedl. - Thomson (1997: 271)
- Lecanora caesiorubella Ach. subsp. caesiorubella - Thomson (2003: 119)
- Lecanora carpinea (L.) Vain. - Thomson (2003: 119)
- Lecanora cateilea (Ach.) A. Massal. - Bennett (2006: )
- Lecanora cenisia Ach. - Thomson (1997: 272), Thomson (2003: 119)
- Lecanora chlarotera Nyl. - Thomson (1997: 273), Thomson (1997: 301 as Lecanora rugosella), Thomson (2003: 119), Thomson (2003: 122 as Lecanora rugosella)
- Lecanora circumborealis Brodo & Vitik. - Thomson (1997: 274), Thomson (2003: 120)
- Lecanora crenulata Hook. - Thomson (1997: 277), Thomson (2003: 120)
- Lecanora dispersa (Pers.) Sommerf. - Thomson (1997: 278), Thomson (2003: 120)
- Lecanora expallens Ach. - Thomson (1997: 280), Bennett (2006: )
- Lecanora fuscescens (Sommerf.) Nyl. - Thomson (2003: )
- Lecanora glabrata (Ach.) Malme - Thomson (2003: 120)
- Lecanora hagenii (Ach.) Ach. - Thomson (1997:286), Thomson (2003: 120)
- Lecanora hybocarpa (Tuck.) Brodo - Thomson (2003: 121)
- Lecanora hypoptoides (Nyl.) Nyl. - Thomson (2003: 121)
- Lecanora intricata (Ach.) Ach.- Thomson (1997: 288), Thomson (2003: 122)
- Lecanora invadens H. Magn. - Bennett (2006: )
- Lecanora iowensis Fink - Thomson (2003: 122)
- Lecanora meridionalis H. Magn. - Lay (2004: )
- Lecanora muralis (Schreber) Rabenh. - Thomson (1997: 295), Thomson (2003: 122)
- Lecanora opiniconensis Brodo - Thomson (2003: 122)
- Lecanora perplexa Brodo - Thomson (1997: 298), Thomson (2003: 123)
- Lecanora polytropa (Ehrh. in Hoffm.) Rabenh. - Thomson (1997: 299), Thomson (2003: 123)
- Lecanora pulicaris (Pers.) Ach. - Thomson (1997: 301), Thomson (2003: 123)
- Lecanora saligna (Schrader) Zahlbr. - Thomson (2003: 124)
- Lecanora sambuci (Pers.) Nyl. - Lay (2004: )
- Lecanora strobilina (Sprengel) Kieffer - Thomson (2003: 124)
- Lecanora subimmergens Vain. - Thomson (2003: 124)
- Lecanora subintricata (Nyl.) Th. Fr. - Thomson (1997: 307), Thomson (2003: 125)
- Lecanora subrugosa Nyl. - Thomson (1997: 308), Thomson (2003: 125)
- Lecanora symmicta (Ach.) Ach. - Thomson (1997: 309), Thomson (2003: 125)
- Lecanora thysanophora R. C. Harris - Thomson (2003: 125)
- Lecanora valesiaca (Müll. Arg.) Stizenb. - Thomson (2003: 126)
- Lecanora varia (Hoffm.) Ach. - Thomson (1997: 311), Thomson (2003: 126)
- Lecanora wisconsinensis H. Magn. - Thomson (2003: 126)
- Lecidea albohyalina (Nyl.) Th. Fr. - Thomson (2003: 44 as Biatora albohyalina)
- Lecidea carnulenta (Tuck.) Fink - Thomson (2003: 127)
- Lecidea cyrtidia Tuck. - Thomson (2003: 127)
- Lecidea lapicida (Ach.) Ach. - Thomson (2003: 127)
- Lecidea nylanderi (Anzi) Th. Fr. - Thomson (1997: 365), Thomson (2003: 128)
- Lecidea plana (J. Lahm) Nyl. - Lay (2004: )
- Lecidea plebeja Nyl. - Thomson (1997: 374), Thomson (2003: 128)
- Lecidea virginiensis Calk. & Nyl. - Thomson (2003: 128)
- Lecidella asema (Nyl.) Knoph & Hertel - Bennett (2006: )
- Lecidella carpathica Körb. - Thomson (1997: 395), Thomson (2003: 129)
- Lecidella elaeochroma (Ach.) Hazwl. - Thomson (2003: 129)
- Lecidella euphorea (Flörke) Hertel - Thomson (1997: 398), Thomson (2003: 130)
- Lecidella patavina (A. Massal.) Knoph & Leuckert - Thomson (1997: 399 as Lecidella inamoena), Thomson (2003: 130)
- Lecidella stigmatea (Ach.) Hertel & Leuck. - Brodo (1967: 212 as Lecidea stigmatea), Thomson (1997: 402), Thomson (2003: 130)
- Leimonis erratica (Körb.) R. C. Harris & Lendemer - Thomson (2003: 147 as Micarea erratica)
- Lempholemma polyanthes (Bernh.) Malme - Bennett (2006: )
- Lepra amara (Ach.) Hafellner - Thomson (2003: 171 as Pertusaria amara)
- Lepra multipunctoides (Dibben) Lendemer & R. C. Harris - Thomson (2003: 172 as Pertusaria multipunctoides)
- Lepraria finkii Nyl. - Thomson (2003: 131 as Lepraria lobificans)
- Lepraria incana (L.) Ach. - Thomson (2003: 131)
- Lepraria membranacea (Dickson) Vain. - Thomson (2003: 132 as Leproloma membranaceum)
- Lepraria neglecta (Nyl.) Erichsen - Thomson (2003: 132), Thomson (2003: 131 erroneously as Lepraria caesioalba), Bennett (2006: erroneously as Lepraria cacuminum)
- Lepraria rigidula (B. de Lesd.) Tønsberg - Lay (2004: )
- Lepraria vouauxii (Hue) R. C. Harris - Thomson (2003: 132 as Leproloma vouauxii)
- Leptogium arsenei Sierk - Thomson (2003: 133), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Leptogium burnetiae C. W. Dodge - Bennett (2006: )
- Leptogium byssinum (Hoffm.) Zwackh - Bennett & Bartkowiak (2013: 72)
- Leptogium corticola (Taylor) Tuck. - Thomson (2003: 133)
- Leptogium cyanescens (Rabenh.) Körb. - Thomson (2003: 134)
- Leptogium hirsutum Sierk - Thomson (2003: 134)
- Leptogium milligranum Sierk - Thomson (2003: 135)
- Leptogium rivulare (Ach.) Mont. - Bennett & Bartkowiak (2013: 73)
- Leptogium saturninum (Dicks.) Nyl. - Thomson (1984: 262), Thomson (2003: 135)
- Lichinella cribellifera (Nyl.) P. P. Moreno & Egea - Bennett (2006: )
- Lichinella nigritella (Lettau) P. P. Moreno & Egea - Thomson (2003: 136)
- Lithothelium hyalosporum (Nyl.) Aptroot - Thomson (2003: 136)
- Lithothelium phaeosporum (R. C. Harris) Aptroot - Thomson (2003: 136)
- Lithothelium septemseptatum (R. C. Harris) Aptroot - Lay (2004: )
- Lobaria pulmonaria (L.) Hoffm. - Thomson (2003: 137)
- Lobaria quercizans Michx. - Thomson (2003: 137)
- Lopadium disciforme (Flot.) Kullhem - Thomson (2003: )
- Lopadium pezizoideum (Ach.) Körb. - Thomson (2003: 138)
- Loxospora cismonica (Beltr.) Hafellner - Thomson (2003: 139)
- Loxospora elatina (Ach.) A. Massal. - Thomson (2003: 139)
- Maronea constans (Nyl.) Hepp - Thomson (2003: 139)
- Megalospora porphyritis (Tuck.) R. C. Harris - Bennett (2006: )
- Megaspora verrucosa (Ach.) Hafellner & Wirth - Thomson (1997: 443 as Pachyospora verrucosa), Thomson (2003: 140)
- Melanelixia albertana (Ahti) O. Blanco et al. - Thomson (2003: 141 as Melanelia albertana)
- Melanelixia fuliginosa (Fr. ex Duby) O. Blanco et al. - Thomson (1984: 303 as Parmelia glabratula), Bennett (2006: )
- Melanelixia subargentifera (Nyl.) O. Blanco et al. - Thomson (2003: 143 as Melanelia subargentifera)
- Melanelixia subaurifera (Nyl.) O. Blanco et al. - Thomson (1984: 316 as Parmelia subaurifera), Thomson (2003: 143 as Melanelia subaurifera)
- Melanohalea exasperata (De Not.) O. Blanco et al. - Thomson (2003: 142 as Melanelia exasperata)
- Melanohalea exasperatula (De Not.) O. Blanco et al. - Thomson (2003: 142 as Melanelia exasperatula)
- Melanohalea olivacea (L.) O. Blanco et al. - Thomson (1984: 306 as Parmelia olivacea), Thomson (2003: 142 as Melanelia olivacea)
- Melanohalea septentrionalis (Lynge) O. Blanco et al. - Thomson (1984: 311 as Parmelia septentrionalis), Thomson (2003: 143 as Melanelia septentrionalis)
- Melanohalea subolivacea (Nyl.) O. Blanco et al. - Thomson (2003: 144 as Melanelia subolivacea)
- Melaspilea arthonioides (Fée) Nyl. - Thomson (2003: 144)
- Melaspilea demissa (Tuck.) Zahlbr. - Thomson (2003: 145)
- Menegazzia terebrata (Hoffm.) A. Massal. - Thomson (2003: 145), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Micarea denigrata (Fr.) Hedl. - Thomson (2003: 146)
- Micarea endocyanea (Tuck. ex Willey) R. C. Harris - Lay (2004: )
- Micarea melaena (Nyl.) Hedl. - Thomson (2003: 147)
- Micarea misella (Nyl.) Hedl. - Bennett (2006: )
- Micarea myriocarpa V. Wirth & Vezda ex Coppins - Thomson (2003: 147)
- Micarea peliocarpa (Anzi) Coppins & R. Sant. - Thomson (2003: 147)
- Micarea prasina Fr. - Thomson (2003: 148)
- Montanelia disjuncta (Erichsen) Divakar, A. Crespo, Wedin & Essl. - Thomson (2003: 140 as Melanelia disjuncta)
- Montanelia sorediata (Ach.) Divakar, A. Crespo, Wedin & Essl. - Thomson (1984: 312 as Parmelia sorediosa), Lay (2003: as Melanelia sorediata)
- Montanelia tominii (Oxner) Divakar, A. Crespo, Wedin & Essl. - Thomson (1984: 317 as Parmelia substygia), Thomson (2003: 144 as Melanelia tominii)
- Multiclavula mucida (Fr.) R. Petersen - Lay (2004: )
- Multiclavula vernalis (Schwein.) R. Petersen - Bennett (2006: )
- Mycobilimbia berengeriana (A. Massal.) Hafellner & V. Wirth - Thomson (1997: 331 as Lecidea berengeriana), Thomson (2003: 149)
- Mycobilimbia carneoalbida (Müll. Arg.) S. Ekman & Printzen - Thomson (1997: 110 as Bacidia sphaeroides), Thomson (2003: 39 as Bacidia carneoalbida)
- Mycobilimbia epixanthoides (Nyl.) Vitikainen et al. - Thomson (2003: 44 as Biatora epixanthoides)
- Mycobilimbia pilularis (Körb.) Hafellner & Türk - Brodo (1967: 212 as Bacidia sphaeroides), Thomson (2003: as )
- Mycobilimbia tetramera (de Not.) W. Brunnbauer - Thomson (1997: 422 as Mycobilimbia obscurata), Thomson (2003: 150)
- Mycoblastus sanguinarius (L.) Norman - Thomson (1997: 426), Thomson (2003: 150)
- Myelochroa aurulenta (Tuck.) Elix & Hale - Thomson (2003: 151)
- Myelochroa galbina (Ach.) Elix & Hale - Thomson (2003: 151)
- Myelochroa obsessa (Ach.) Elix & Hale - Thomson (2003: 151)
- Myriospora smaragdula (Wahlenb. in Ach.) K. Knudsen & B. Abbott - Thomson (1997: 34 as Acarospora smaragdula), Bennett (2006: as Acarospora smaragdula)
- Nephroma bellum (Spreng.) Tuck. - Thomson (1984: 278), Thomson (2003: 152), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Nephroma helveticum Ach. var. helveticum - Thomson (1984: 280), Thomson (2003: 152)
- Nephroma parile (Ach.) Ach. - Thomson (1984: 282), Thomson (2003: 153)
- Normandina pulchella (Borrer) Nyl. - Lay (2004: )
- Ochrolechia androgyna (Hoffm.) Arnold - Thomson (1997: 430), Thomson (2003: 154)
- Ochrolechia arborea (Kreyer) Almb. - Thomson (2003: 154)
- Ochrolechia mexicana Vain. - Thomson (2003: 154)
- Ochrolechia pseudopallescens Brodo - Thomson (2003: 154)
- Ochrolechia trochophora (Vain.) Oshio var. pruinirosella Brodo - Brodo (1991: 763 Type), Kukwa (2009: 43)
- Ochrolechia trochophora (Vain.) Oshio var. trochophora - Thomson (2003: 155)
- Opegrapha vulgata Ach. - Lay (2004: )
- Pachypeltis invadens (Lynge) Søchting, Frödén & Arup - Thomson (2003: 56 as Caloplaca invadens)
- Pannaria conoplea (Ach.) Bory - Thomson (1984: 292), Thomson (2003: 157)
- Pannaria rubiginosa (Thunb.) Delise - Thomson (2003: 158)
- Parmelia fraudans (Nyl.) Nyl. - Thomson (2003: 158)
- Parmelia saxatilis (L.) Ach. - Thomson (1984: 310), Thomson (2003: 159)
- Parmelia squarrosa Hale - Thomson (1984: 313), Thomson (2003: 159)
- Parmelia sulcata Tayl. - Thomson (1984: 318), Thomson (2003: 159)
- Parmeliopsis ambigua (Wulf.) Nyl. - Thomson (1984: 325), Thomson (2003: 160)
- Parmeliopsis capitata R. C. Harris ex J. W. Hinds & P. L. Hinds - Thomson (2003: 160)
- Parmeliopsis hyperopta (Ach.) Arnold - Thomson (1984: 326), Thomson (2003: 160)
- Parmotrema arnoldii (Du Rietz) Hale - Thomson (2003: 161)
- Parmotrema crinitum (Ach.) Choisy - Thomson (2003: 162)
- Parmotrema hypotropum (Nyl.) Hale - Thomson (2003: 162)
- Parmotrema margaritatum (Hue) Hale - Thomson (2003: 162)
- Parmotrema perforatum (Jacq.) A. Massal. - Thomson (2003: 162), Bennett & Wetmore (2004: 173 Extinct)
- Parmotrema perlatum (Osbeck) Hale & Ahti - Thomson (2003: 161 as Parmotrema chinense), Bennett & Wetmore (2004: 172 as Parmotrema chinense Historical Occurrences)
- Parmotrema reticulatum (Taylor) M. Choisy - Thomson (2003: as Rimelia reticulatum)
- Parmotrema stuppeum (Taylor) Hale - Thomson (2003: ), Bennett & Wetmore (2004: 172 Historical Occurrences)
- Parmotrema subtinctorium (Zahlbr.) Elix - Thomson (2003: as Canomaculina subtinctoria)
- Parvoplaca tiroliensis Zahlbr. - Thomson (1997: 173 as Caloplaca tiroliensis), Thomson (2003: 58 as Caloplaca tiroliensis)
- Peltigera aphthosa (L.) Willd. - Thomson (1984: 329), Thomson (2003: 166)
- Peltigera canina (L.) Willd. - Thomson (2003: 166)
- Peltigera degenii Gyelnik - Thomson (2003: 166)
- Peltigera didactyla (With.) J. R. Laundon - Thomson (2003: 167)
- Peltigera evansiana Gyelnik - Brodo (1967: 212), Thomson (2003: 167)
- Peltigera horizontalis (Huds.) Baumg. - Brodo (1967: 212), Thomson (1984: 337), Thomson (2003: 167)
- Peltigera lepidophora (Nyl.) Vain. - Brodo (1967: 212), Thomson (1984: 338), Thomson (2003: 168)
- Peltigera leucophlebia (Nyl.) Gyelnik - Thomson (1984: 330 as Peltigera aphthosa var. leucophlebia)
- Peltigera malacea (Ach.) Funck. - Thomson (1984: 339), Thomson (2003: 168)
- Peltigera membranacea (Ach.) Nyl. - Thomson (2003: 168)
- Peltigera neckeri Hepp ex Müll. Arg. - Bennett (2006: )
- Peltigera polydactylon (Neck.) Hoffm. - Thomson (1984: 343), Thomson (2003: 169)
- Peltigera praetextata (Flörke ex Sommerf.) Zopf - Brodo (1967: 212)
- Peltigera rufescens (Weiss) Humb. - Brodo (1967: 212 as Peltigera canina var. rufescens), Thomson (2003: 169)
- Peltigera scabrosa Th. Fr. - Thomson (2003: 169), Bennett & Wetmore (2004: 172 Critically Imperiled)
- Peltigera venosa (L.) Hoffm. - Thomson (2003: 170), Bennett & Wetmore (2004: 173 Historical Occurrences)
- Pertusaria alpina Hepp ex Ahles - Thomson (2003: 171)
- Pertusaria consocians Dibben - Thomson (2003: 171)
- Pertusaria leioplaca (Ach.) DC. - Thomson (2003: 172)
- Pertusaria macounii (I. M. Lamb) Dibben - Thomson (2003: 172)
- Pertusaria neoscotica I. M. Lamb - Thomson (2003: 172)
- Pertusaria plittiana Erichsen - Thomson (2003: 173)
- Pertusaria pustulata (Ach.) Duby - Thomson (2003: 173)
- Pertusaria rubefacta Erichsen - Thomson (2003: 174)
- Pertusaria tetrathalamia (Fée) Nyl. - Thomson (2003: 174)
- Pertusaria xanthodes Müll. Arg. - Thomson (2003: 175)
- Phaeophyscia adiastola (Essl.) Essl. - Thomson (2003: 177)
- Phaeophyscia ciliata (Hoffm.) Moberg - Thomson (2003: 178)
- Phaeophyscia endococcina (Körb.) Moberg - Thomson (1984: 348), Thomson (2003: 178)
- Phaeophyscia erythrocardia (Tuck.) Essl. - Thomson (2003: 178)
- Phaeophyscia hirsuta (Mereschk.) Essl. - Thomson (2003: 177 as Phaeophyscia cernohorskyi)
- Phaeophyscia hirtella Essl. - Thomson (2003: 178)
- Phaeophyscia hispidula (Ach.) Essl. - Thomson (2003: 179), Thomson (2003: 179)
- Phaeophyscia kairamoi (Vain.) Moberg - Thomson (2003: 179)
- Phaeophyscia nigricans (Flörke) Moberg - Thomson (2003: 180)
- Phaeophyscia orbicularis (Neck.) Moberg - Thomson (2003: 180)
- Phaeophyscia pusilloides (Zahlbr.) Essl. - Thomson (2003: 180)
- Phaeophyscia rubropulchra (Degel.) Moberg - Thomson (2003: 180)
- Phaeophyscia sciastra (Ach.) Moberg - Thomson (1984: 349), Thomson (2003: 180)
- Phaeophyscia squarrosa Kashiw. - Thomson (2003: 179 as Phaeophyscia imbricata)
- Phlyctis argena (Ach.) Flot. - Thomson (2003: 181)
- Phylliscum demangeonii (Moug. & Mont.) Nyl. - Thomson (2003: 181)
- Physcia adscendens H. Olivier - Thomson (1984: 352), Thomson (2003: 183)
- Physcia aipolia (Ehrh. ex Humb.) Fürnr. - Thomson (1984: 353), Thomson (2003: 183)
- Physcia americana G. Merr. - Thomson (2003: 183)
- Physcia caesia (Hoffm.) Fürnr. - Thomson (1984: 354), Thomson (2003: 184)
- Physcia dubia (Hoffm.) Lettau - Thomson (1984: 355), Thomson (2003: 184)
- Physcia halei J. W. Thomson - Thomson (2003: 184)
- Physcia millegrana Degel. - Thomson (2003: 184)
- Physcia phaea (Tuck.) J. W. Thomson - Thomson (1984: 356), Thomson (2003: 185)
- Physcia stellaris (L.) Nyl. - Thomson (2003: 185)
- Physcia subtilis Degel. - Thomson (2003: 185)
- Physcia tenella (Scop.) DC. - Thomson (2003: 185), Bennett & Wetmore (2004: 173 Critically Imperiled)
- Physciella chloantha (Ach.) Essl. - Thomson (2003: 186)
- Physciella melanchra (Hue) Essl. - Thomson (2003: 186), Bennett & Wetmore (2004: 173 Imperiled)
- Physconia americana Essl. - Lay (2004: )
- Physconia detersa (Nyl.) Poelt - Thomson (1984: 359), Thomson (2003: 187)
- Physconia leucoleiptes (Tuck.) Essl. - Thomson (2003: 188)
- Physconia perisidiosa (Erichsen) Moberg - Thomson (2003: 188)
- Piccolia ochrophora (Nyl.) Hafellner - Thomson (2003: 224 as Strangospora ochrophora)
- Placidium arboreum (Schwein. ex Michener) Lendemer - Thomson (2003: 63 as Catapyrenium tuckermanii)
- Placidium lachneum (Ach.) Breuss - Thomson (1984: 217 as Dermatocarpon lachneum), Thomson (2003: ), Thomson (2003: 62 as Catapyrenium lachneum)
- Placidium lacinulatum (Ach.) Breuss - Thomson (2003: )
- Placidium rufescens (Ach.) Breuss - Thomson (2003: 63 as Catapyrenium rufescens)
- Placidium squamulosum (Ach.) Breuss - Brodo (1967: 211 as Dermatocarpon hepaticum), Thomson (1984: 215 as Dermatocarpon hepaticum), Thomson (2003: 63 as Catapyrenium squamulosum)
- Placopyrenium fuscellum (Turner) Gueidan & Cl. Roux - Thomson (2003: 243 as Verrucaria fuscella)
- Placynthiella dasaea (Stirt.) Tøberg - Bennett (2006: )
- Placynthiella icmalea (Ach.) Coppins & P. James - Thomson (2003: 189)
- Placynthiella oligotropha (J. R. Laundon) Coppins & P. James - Thomson (2003: 189)
- Placynthiella uliginosa (Schrad.) Coppins & James - Thomson (1997: 475), Thomson (2003: 189)
- Placynthium asperellum (Ach.) Trevisan - Thomson (1984: 365 as Placynthium aspratile), Thomson (2003: 190)
- Placynthium nigrum (Huds.) Gray - Thomson (1984: 366), Thomson (2003: 190)
- Placynthium stenophyllum (Tuck.) Fink - Thomson (2003: 190)
- Platismatia glauca (L.) W. L. Culb. & C. F. Culb. - Thomson (2003: 191)
- Platismatia tuckermanii (Oakes) W. L. Culb. & C. F. Culb. - Thomson (2003: 191)
- Pleopsidium chlorophanum (Wahlenb.) Zopf - Douglas (1974: 584 sub Acarospora chlorophana), Thomson (2003: 25 as Acarospora chlorophana)
- Pleopsidium flavum (Bellardi) Körb. - Bennett (2006: )
- Polycauliona candelaria (L.) Frödén, Arup, & Søchting - Thomson (1984: 483 as Xanthoria candelaria)
- Polycauliona polycarpa (Hoffm.) Frödén, Arup, & Søchting - Thomson (1984: 487 as Xanthoria polycarpa), Thomson (2003: 250 as Xanthoria polycarpa)
- Polysporina simplex (Taylor) Vezda - Thomson (1997: 486), Thomson (2003: 192)
- Porpidia albocaerulescens (Wulfen) Hertel & Knoph - Thomson (2003: 193)
- Porpidia contraponenda (Arnold) Knoph & Hertel - Bennett (2006: )
- Porpidia crustulata (Ach.) Hertel & Knoph - Thomson (2003: 193)
- Porpidia cinereoatra Gowan - Thomson (2003: 193 as Porpidia herteliana)
- Porpidia macrocarpa (DC.) Hertel & A. J. Schwab - Thomson (2003: 194)
- Porpidia speirea (Ach.) Kremp. - Thomson (1997: 497)
- Porpidia tuberculosa (Sm.) Hertel & Knoph - Lay (2004: )
- Protoblastenia rupestris (Scop.) Steiner - Thomson (1997: 503), Thomson (2003: 194)
- Protopannaria pezizoides (Weber) P. M. Jørg. & S. Ekman - Thomson (1984: 294 as Pannaria pezizoides), Thomson (2003: 157 as Pannaria pezizoides), Bennett & Wetmore (2004: 173 Historical Occurrences)
- Pseudevernia consocians (Vain.) Hale & W. L. Culb. - Thomson (2003: 195), Bennett & Wetmore (2004: 173 Critically Imperiled)
- Pseudocyphellaria crocata (L.) Vain. - Thomson (2003: 195), Bennett & Wetmore (2004: 173 Critically Imperiled)
- Pseudosagedia cestrensis (Tuck. ex E. Michener) R. C. Harris - Thomson (2003: 192 as Porina cestrensis)
- Psilolechia lucida (Ach.) M. Choisy - Thomson (2003: 196)
- Psora decipiens (Hedwig) Hoffm. - Brodo (1967: 212 as Lecidea decipiens), Thomson (1997: 507), Thomson (2003: 197)
- Psora pseudorussellii Timdal - Thomson (2003: 197)
- Psora russellii (Tuck.) A. Schneider - Brodo (1967: 212 as Lecidea russellii), Thomson (2003: 197)
- Psorotichia schaereri (A. Massal.) Arnold - Thomson (2003: 198)
- Psorula rufonigra (Tuck.) Gotth. Schneider - Thomson (1997: 515), Thomson (2003: 198)
- Punctelia bolliana (Müll. Arg.) Krog - Thomson (2003: 199)
- Punctelia hypoleucites (Nyl.) Krog - Thomson (2003: 199)
- Punctelia missouriensis G. Wilh. & Ladd - Thomson (2003: )
- Punctelia perreticulata (Räsänen) Wilhelm & Ladd - Thomson (2003: 199)
- Punctelia punctilla (Hale) Krog - Thomson (2003: 200)
- Punctelia rudecta (Ach.) Krog - Thomson (2003: 200)
- Puttea caesia (Fr.) M. Svensson & T. Sprib. - Bennett (2006: as Lecidea symmictella)
- Pycnothelia papillaria (Ehrh.) Duf. - Thomson (1984: 377), Thomson (2003: 201)
- Pyrenopsis phaeococca Tuck. - Thomson (2003: 201)
- Pyrenula laevigata (Pers.) Arnold - Lay (2004: )
- Pyrenula pseudobufonia (Rehm) R. C. Harris - Thomson (2003: 202)
- Pyxine sorediata (Ach.) Mont. - Thomson (2003: 203)
- Ramalina americana Hale - Thomson (2003: 204)
- Ramalina dilacerata (Hoffm.) Hoffm. - Thomson (2003: 204)
- Ramalina farinacea (L.) Ach. - Thomson (2003: 204), Bennett & Wetmore (2004: 173 Critically Imperiled)
- Ramalina intermedia (Del. ex Nyl.) Nyl. - Thomson (1984: 379), Thomson (2003: 204)
- Ramalina obtusata (Arnold) Bitter - Thomson (1984: 380), Thomson (2003: 205)
- Ramalina pollinaria (Westr.) Ach. - Thomson (2003: 205), Bennett & Wetmore (2004: 173 Historical Occurrences)
- Ramalina sinensis Jatta - Thomson (2003: 205)
- Ramalina unifolia J. W. Thomson - Thomson (1990: 341), Thomson (2003: 205), Bennett & Wetmore (2004: 173 Critically Imperiled)
- Ramboldia elabens (Fr.) Kantvilas & Elix - Thomson (2003: 202 as Pyrrhospora elabens)
- Rhizocarpon cinereovirens (Müll.Arg.) Vain. - Thomson (1997: 528), Thomson (2003: 206)
- Rhizocarpon concentricum (Davis) Beltr. - Thomson (1997: 529), Thomson (2003: 207)
- Rhizocarpon disporum (Nägeli ex Hepp) Müll. Arg. - Thomson (2003: 207)
- Rhizocarpon distinctum Th. Fr. - Thomson (2003: 207)
- Rhizocarpon eupetraeum (Nyl.) Arnold - Thomson (1997: 533), Thomson (2003: 208)
- Rhizocarpon geminatum Körb. - Thomson (1997: 537)
- Rhizocarpon grande (Flörke ex Flot.) Arnold - Thomson (1997: 539), Thomson (2003: 208)
- Rhizocarpon obscuratum auct. - Thomson (1997: 545), Thomson (2003: 208)
- Rhizocarpon oederi (Weber) Körb. - Thomson (2003: 208)
- Rhizocarpon petraeum (Wulfen) A. Massal. - Bennett (2006: )
- Rhizocarpon rubescens Th. Fr. sensu Fryday - Lay (2004: )
- Rhizocarpon tetramerum (Vain.) Vain. - Thomson (2003: 208)
- Rhizoplaca chrysoleuca (Sm.) Zopf - Thomson (1997: 554), Thomson (2003: 209)
- Rhizoplaca melanophthalma (Ramond) Leuck. & Poelt - Thomson (1997: 555), Thomson (2003: 210)
- Rhizoplaca subdiscrepans (Nyl.) R. Sant. - Thomson (2003: 210)
- Rinodina adirondackii H. Magn. - Bennett (2006: )
- Rinodina archaea (Ach.) Vain. - Thomson (1997: 560), Thomson (2003: 211)
- Rinodina ascociscana Tuck. - Thomson (2003: 212)
- Rinodina bischoffii (Hepp.) A. Massal. - Thomson (1997: 561), Thomson (2003: 212)
- Rinodina cana (Arnold) Arnold - Thomson (2003: 214 as Rinodina iowensis)
- Rinodina confragosa (Ach.) Körb. - Thomson (2003: 212)
- Rinodina degeliana Coppins - Thomson (2003: 212)
- Rinodina destituta H. Mayrhofer - Bennett (2006: as Rinodina vezdae)
- Rinodina efflorescens Malme - Thomson (2003: 213)
- Rinodina excrescens Vain. - Magnusson (1953: 192 as Rinodina marysvillensis var. thujae Type), Sheard (1987: 164 as Rinodina thujae), Sheard (1995: 119), Thomson (2003: 213)
- Rinodina freyi H. Magn. - Thomson (2003: 213 as Rinodina glauca)
- Rinodina oxydata (A. Massal.) A. Massal. - Thomson (2003: 214)
- Rinodina pachysperma H. Magn. - Magnusson (1953: 193 Type in WIS), Thomson (2003: 214), Sheard (2010: 156)
- Rinodina papillata H. Magn. - Magnusson (1953: 194 Type in U), Thomson (2003: 215), Sheard (2010: 159)
- Rinodina populicola H. Magn. - Magnusson (1953: 167 Type in Uppsala, Sweden UPS), Thomson (2003: 215), Sheard (2010: 167)
- Rinodina pyrina (Ach.) Arnold - Thomson (2003: 215)
- Rinodina sibirica H. Magn. - Thomson (2003: 214 erroneously as Rinodina granulans)
- Rinodina subminuta H. Magn. - Thomson (2003: 215)
- Rinodina tephraspis (Tuck.) Herre - Thomson (2003: 216)
- Rinodina turfacea (Wahlenb.) Körb. - Thomson (2003: 216)
- Romjularia lurida (Ach.) Timdal - Thomson (2003: 128 as Lecidea lurida)
- Rufoplaca arenaria (Pers.) Arup, Søchting & Frödén - Thomson (2003: 54 as Caloplaca arenaria)
- Rufoplaca oxfordensis (Fink) Arup, Søchting & Frödén - Thomson (2003: 57 as Caloplaca oxfordensis)
- Rusavskia elegans (Link) S. Y. Kondr. & Kärnefelt - Thomson (1984: 484 as Xanthoria elegans), Thomson (2003: 248 as Xanthoria elegans)
- Rusavskia sorediata (Vain.) S. Y. Kondr. & Kärnefelt - Thomson (1984: 487 as Xanthoria sorediata), Thomson (2003: 250 as Xanthoria sorediata)
- Sarcogyne clavus (DC. in Lam. & DC.) Kremp. - Brodo (1967: 212), Thomson (1997: 577), Thomson (2003: 216)
- Sarcogyne hypophaea (Ach.) A. Massal. - Thomson (2003: 217 erroneously as Sarcogyne privigna)
- Sarcogyne regularis Körb. - Brodo (1967: 212), Thomson (1997: 579), Thomson (2003: 217)
- Sclerophora nivea (Hoffm.) Tibell - Lay (2004: )
- Scoliciosporum chlorococcum (Stenh.) Vezda - Thomson (2003: 218)
- Scoliciosporum umbrinum (Ach.) Arnold - Thomson (1997: 585), Thomson (2003: 218)
- Scytinium dactylinum (Tuck.) Otálora, P. M. Jørg. & Wedin - Bennett & Bartkowiak (2013: 73 as Leptogium dactylinum)
- Scytinium intermedium (Arnold) Otálora, P. M. Jørg. & Wedin - Thomson (2003: 134 as Leptogium intermedium)
- Scytinium lichenoides (L.) Otálora, P. M. Jørg. & Wedin - Thomson (1984: 257 as Leptogium lichenoides), Thomson (2003: 134 as Leptogium lichenoides)
- Scytinium subtile (Schrad.) Otálora, P. M. Jørg. & Wedin - Thomson (1984: 259 as Leptogium minutissimum)
- Scytinium teretiusculum (Wallr.) Otálora, P. M. Jørg. & Wedin - Thomson (2003: 135 as Leptogium teretiusculum), Bennett & Wetmore (2004: 172 as Leptogium teretiusculum Critically Imperiled)
- Solitaria chrysophthalma (Degel.) Arup, Søchting & Frödén - Thomson (2003: 55 as Caloplaca chrysophthalma)
- Solorina saccata (L.) Ach. - Thomson (1984: 390), Thomson (2003: 218), Bennett & Wetmore (2004: 173 Historical Occurrences)
- Spilonema revertens Nyl. - Bennett (2006: )
- Squamulea galactophylla (Tuck.) Arup, Søchting & Frödén - Thomson (2003: 54 as Caloplaca galactophylla)
- Squamulea subsoluta (Nyl.) Arup, Søchting & Frödén - Bennett (2006: as Caloplaca subsoluta)
- Staurothele areolata (Ach.) Lettau - Brodo (1967: 211 as Staurothele clopima), Thomson (1997: 592), Thomson (2003: 220)
- Staurothele drummondii (Tuck.) Tuck. - Thomson (2003: 220)
- Staurothele fissa (Tayler) Zwackh. - Thomson (1997: 596), Thomson (2003: 220)
- Staurothele monicae (Zahlbr.) Wetmore - Bennett (2006: )
- Stereocaulon condensatum Hoffm. - Thomson (1984: 407), Thomson (2003: 222)
- Stereocaulon paschale (L.) Hoffm. - Thomson (1984: 418), Thomson (2003: 222)
- Stereocaulon saxatile H. Magn. - Thomson (1984: 423), Thomson (2003: 222)
- Stereocaulon tomentosum E. Fries - Thomson (1984: 428), Thomson (2003: 223)
- Sticta beauvoisii Delise - Thomson (1984: 434 falso sub Sticta weigelii), Thomson (2003: 223), Bennett & Wetmore (2004: 173 Critically Imperiled)
- Sticta fuliginosa (Hoffm.) Ach. - Lay (2004: )
- Stictis urceolatum (Ach.) Gilenstam - Thomson (2003: 95 as Conotrema urceolatum)
- Strangospora deplanata (Almq.) Poelt & Vezda - Thomson (2003: 224)
- Strangospora microhaema (Norman) R. Anderson - Thomson (2003: 224)
- Strangospora pinicola (A. Massal.) Körb. - Bennett (2006: )
- Strigula americana R. C. Harris - Thomson (2003: 225)
- Strigula stigmatella (Ach.) R. C. Harris - Thomson (2003: 225)
- Strigula submuriformis (R. C. Harris) R. C. Harris - Thomson (2003: 225)
- Teloschistes chrysophthalmus (L.) Th. Fr. - Thomson (2003: 226), Bennett & Wetmore (2004: 173 Historical Occurrences)
- Tephromela atra (Huds.) Hafellner - Thomson (1997: 633), Thomson (2003: 226)
- Thelenella pertusariella (Nyl.) Vain. - Lay (2004: )
- Thelidium fontigenum A. Massal. - Thomson (2003: 227 as Thelidium microbolum)
- Thelocarpon laureri (Flot.) Nyl. - Thomson (2003: 227)
- Thrombium epigaeum (Pers.) Wallr. - Thomson (1997: 610), Thomson (2003: 227)
- Thyrea confusa Henssen - Thomson (2003: 228)
- Toninia sedifolia (Scop.) Timdal - Thomson (1997: 614 as Toninia caeruleonigricans), Thomson (2003: 228)
- Trapelia coarctata (Turner ex Sm. & Sow.) M. Choisy - Thomson (1997: 621), Thomson (2003: 229)
- Trapelia glebulosa (Sm.) J. R. Laundon - Thomson (2003: 229 as Trapelia involuta)
- Trapelia obtegens (Th. Fr.) Hertel, Thomson (2003: 229)
- Trapelia placodioides Coppins & P. James - Thomson (2003: 230)
- Trapeliopsis flexuosa (Fr.) Coppins & James - Thomson (1997: 623), Thomson (2003: 230)
- Trapeliopsis gelatinosa (Flörke) Coppins & P. James - Thomson (2003: 231)
- Trapeliopsis granulosa (Hoffm.) Lumbsch - Thomson (1997: 624), Thomson (2003: 231)
- Trapeliopsis viridescens (Schrad.) Coppins & James - Thomson (1997: 625), Thomson (2003: 231)
- Tremolecia atrata (Ach.) Hertel - Thomson (1997: 627), Thomson (2003: 232)
- Trypethelium virens Tuck. ex E. Michener - Thomson (2003: 232)
- Tuckermanella fendleri (Nyl.) Essl. - Thomson (2003: 233 as Tuckermanopsis fendleri)
- Tuckermanopsis americana (Sprengel) Hale - Thomson (1984: 81 as Cetraria halei), Thomson (2003: 233)
- Tuckermanopsis ciliaris (Ach.) Gyelnik - Thomson (2003: 233)
- Tuckermanopsis orbata (Nyl.) M.-J. Lai - Thomson (2003: 234)
- Tuckermanopsis sepincola (Ehrh.) Hale - Thomson (1984: 94 as Cetraria sepincola), Thomson (2003: 234)
- Umbilicaria americana Poelt & T. H. Nash - Thomson (2003: 234)
- Umbilicaria deusta (L.) Baumg. - Lay (2004: )
- Umbilicaria lyngei Schol. - Llano (1950: as Agyrophora lyngei), Douglas (1974: 584 as Agyrophora lyngei)
- Umbilicaria mammulata (Ach.) Tuck. - Thomson (2003: 235)
- Umbilicaria muehlenbergii (Ach.) Tuck. - Thomson (1984: 26 as Actinogyra muhlenbergii), Thomson (2003: 234)
- Umbilicaria vellea (L.) Ach. - Thomson (1984: 460)
- Usnea angulata Ach. - Thomson (2003: 236), Bennett & Wetmore (2004: 173 Extinct)
- Usnea cavernosa Tuck. - Thomson (2003: 237)
- Usnea ceratina Ach. - Thomson (2003: 237), Bennett & Wetmore (2004: 173 Imperiled)
- Usnea filipendula Stirt. - Thomson (2003: 237)
- Usnea fulvoreagens (Räsänen) Räsänen - Lay (2004: )
- Usnea glabrata (Ach.) Vain. - Thomson (2003: 237)
- Usnea glabrescens (Nyl. ex Vain.) Vain. ex Räsänen - Thomson (2003: 238)
- Usnea halei P. Clerc - Thomson (2003: 238)
- Usnea hirta (L.) F. H. Wigg.- Thomson (1984: 466), Thomson (2003: 238)
- Usnea lapponica Vain. - Thomson (2003: 238)
- Usnea longissima Ach. - Thomson (2003: 239), Bennett & Wetmore (2004: 173 Extinct)
- Usnea mutabilis Stirt. - Thomson (2003: 239)
- Usnea rubicunda Stirt. - Thomson (2003: 239 as Usnea pensylvanica), Thomson (2003: 240), Bennett & Wetmore (2004: 173 Extinct)
- Usnea strigosa (Ach.) Eaton subsp. strigosa - Thomson (2003: 240)
- Usnea subfloridiana Stirt. - Thomson (1984: 469), Thomson (2003: 240)
- Usnea subfusca Stirt. - Thomson (2003: 240)
- Usnea substerilis Motyca - Thomson (1984: 470)
- Usnea trichodea Ach. - Thomson (2003: 241), Bennett & Wetmore (2004: 173 Imperiled)
- Usnocetraria oakesiana (Tuck.) M. J. Lai & C. J. Wei - Thomson (2003: 233 as Tuckermanopsis oakesiana)
- Vahliella leucophaea (Vahl) P. M. Jørg. - Thomson (2003: 104 as Fuscopannaria leucophaea), Bennett & Wetmore (2004: 172 as Fuscopannaria leucophaea Historical Occurrences)
- Varicellaria velata (Turner) Schmitt & Lumbsch - Thomson (2003: 175 as Pertusaria velata)
- Variolaria ophthalmiza Nyl. - Thomson (2003: 173 as Pertusaria ophthalmiza)
- Variolaria pustulata (Brodo & W. L. Culb.) Lendemer, Hodkinson & R. C. Harris - Thomson (2003: 139 as Loxospora pustulata)
- Variolaria trachythallina (Erichsen) Lendemer, Hodkinson & R. C. Harris - Thomson (2003: 174 as Pertusaria trachythallina)
- Verrucaria aethiobola Wahlenb. - Thomson (1997: 632), Thomson (2003: 242)
- Verrucaria calkinsiana Servít - Brodo (1967: 211), Thomson (2003: 242)
- Verrucaria fayettensis Servít - Thomson (2003: )
- Verrucaria glaucovirens Grummann - Thomson (2003: 243)
- Verrucaria margacea (Wahlenb. in Ach.) Wahlenb. - Thomson (1997: 639), Thomson (2003: 243)
- Verrucaria muralis Ach. - Thomson (1997: 641), Thomson (2003: 244)
- Verrucaria nigrescens Pers. - Brodo (1967: 211), Thomson (1997: 642), Thomson (2003: 244)
- Verrucaria nigrescentoidea Fink - Thomson (2003: 244)
- Verrucaria pseudonigrescens Servít - Thomson (2003: 244)
- Verrucaria rupestris Schrad. - Brodo (1967: 211), Thomson (1997: 643)
- Verrucaria viridigrana Breuss - Lay (2004: )
- Verrucaria viridula (Schrad.) Ach. - Thomson (2003: 244)
- Vulpicida pinastri (Scop.) J.-E. Mattsson & M.-J. Lai - Thomson (1984: 93 as Cetraria pinastri), Thomson (2003: 245)
- Xanthocarpia feracissima (H. Magn.) Frödén, Arup & Søchting - Magnusson (1953: 189 as Caloplaca feracissima Type), Thomson (2003: 55 as Caloplaca feracissima)
- Xanthocarpia lactea (A. Massal.) A. Massal. - Thomson (2003: 57 as Caloplaca lactea)
- Xanthomendoza fallax (Hepp in Arnold) Søchting, Kärnefelt & S. Kondr. - Thomson (1984: 486 as Xanthoria fallax), Thomson (2003: 249 as Xanthoria fallax)
- Xanthomendoza fulva (Hoffm.) Söchting, Kärnefelt & S. Kondr. - Thomson (2003: 249 as Xanthoria fulva)
- Xanthomendoza hasseana (Räsänen) Søchting, Kärnefelt & S. Y. Kondr. - Thomson (2003: 249 as Xanthoria hasseana)
- Xanthomendoza ulophyllodes (Räsänen) Söchting, Kärnefelt & S. Kondr. - Thomson (2003: 250 as Xanthoria ulophyllodes)
- Xanthoparmelia angustiphylla (Gyeln.) Hale - Thomson (2003: 246)
- Xanthoparmelia conspersa (Ehrh. ex Ach.) Hale - Thomson (2003: 246)
- Xanthoparmelia cumberlandia (Gyeln.) Hale - Thomson (2003: 246)
- Xanthoparmelia dierythra (Hale) Hale - Thomson (2003: 247)
- Xanthoparmelia hypofusca (Gyeln.) B. P. Hodk. & Lendemer - Thomson (2003: 248 erroneously as Xanthoparmelia tasmanica)
- Xanthoparmelia norhypopsila Hale - Bennett (2006: )
- Xanthoparmelia plittii (Gyeln.) Hale - Thomson (2003: 247)
- Xanthoparmelia stenophylla (Ach.) Ahti & D. Hawksw. - Thomson (2003: 247 as Xanthoparmelia somloensis)
- Xanthoparmelia subramigera (Gyeln.) Hale - Thomson (2003: 247)
- Xanthoparmelia viriduloumbrina (Gyeln.) Lendemer - Thomson (1984: 480 erroneously as Xanthoparmelia taractica)
- Xylographa opegraphella Nyl. - Bennett (2006: )
- Xylopsora friesii (Ach.) Bendiksby & Timdal - Thomson (1997: 247 as Hypocenomyce friesii), Thomson (2003: 109 as Hypocenomyce friesii)
- Zwackhia prosodea (Afzel.) Ertz - Thomson (2003: 156 as Opegrapha prosodea)
- Zwackhia viridis (Ach.) Poetsch & Schied. - Thomson (2003: 156 as Opegrapha viridis)