- Acarospora americana H. Magn. - Eyerdam (1960: 107)
- Acarospora fuscata (Nyl.) Arnold - Douglas (1974: 584), Thomson (1997: 24)
- Acarospora oxytona (Ach.) A. Massal. - Thomson (1997: 29)
- Acarospora schleicheri (Ach.) A. Massal. - Thomson (1997: 33)
- Acarospora smaragdula (Wahlenb. in Ach.) A. Massal. - Thomson (1997: 34)
- Acarospora washingtonensis H. Magn. - Douglas (1974: 584)
- Agyrophora lyngei (Schol.) Llano - Douglas (1974: 584), Thomson (1984: 30)
- Agyrophora rigida (DR.) Llano - Thomson (1984: 31)
- Agyrophora scholanderi Llano - Thomson (1984: 32)
Alectoria cana - Eyerdam (1960: 107)
- Alectoria nigricans (Ach.) Nyl. - Douglas (1974: 584), Thomson (1984: 35)
- Alectoria ochroleuca (Hoffm.) A. Massal. - Douglas (1974: 584)
- Alectoria sarmentosa (Ach.) Ach. - Douglas (1974: 584)
- Alectoria vexillifera (Nyl.) Stitz. - Thomson (1984: 38)
- Amandinea punctata (Hoffm.) Coppins & Scheid. - Thomson (1997: 138 sub Buellia punctata)
- Amygdalaria paneola (Ach.) Hertel & Brodo - Thomson (1997: 42)
- Arthonia radiata (Pers.) Ach. - Douglas (1974: 584)
- Arthopyrenia analeptella (Nyl.) Arnold - Douglas (1974: 584)
- Arthopyrenia sublitoralis (Leighton) Arnold - Thomson (1997: 49)
- Aspicilia aliena (Zahlbr.) Oxner - Thomson (1997: 58)
- Aspicilia caesiocinerea (Nyl. ex Malbr.) Arnold - Thomson (1997: 65)
- Aspicilia cinerea (L.) Körb. s.l. - Thomson (1997: 68)
- Aspicilia subertegens Arnold - Thomson (1997: 95)
- Bacidia albescens (Kremp.) Zw. - Douglas (1974: 584)
- Bacidia rubella (Hoffm.) A. Massal. - Thomson (1997: 107)
- Baeomyces rufus (Huds.) Rebent. - Douglas (1974: 584), Thomson (1984: 52)
- Bellemerea alpina (Sommerf.) Clauz. & Roux - Thomson (1997: 115)
- Bellemerea cinereorufescens (Ach.) Clauz. & Roux - Thomson (1997: 116)
- Biatorella hemispaerica Anzi - Thomson (1997: 119)
- Biatorella kulshanensis Herre - Douglas (1974: 584)
- Brodoa intestiniformis xxx - Douglas (1974: 586 as Hypogymnia intestiniformis)
- Bryonora castanea (Hepp) Poelt - Thomson (1997: 122)
- Bryoria capillaris (Ach.) Brodo & D. Hawksw. - Thomson (1984: 55)
- Bryoria chalybeiformis (L.) Brodo & D. Hawksw. - Thomson (1984: 56)
- Bryoria fremontii Tuck. - Douglas (1974: 584 sub Alectoria fremontii)
- Bryoria fuscescens (Gyeln.) Brodo & D. Hawksw. - Douglas (1974: 584 sub Alectoria jubata), Thomson (1984: 57)
- Bryoria glabra (Mot.) Brodo & D. Hawksw. - Douglas (1974: 584 sub Alectoria glabra), Thomson (1984: 58)
- Bryoria lanestris (Ach.) Brodo & D. Hawksw. - Thomson (1984: 59)
- Bryoria pseudocapillaris Brodo & D. Hawksw. - Geiser et al. (2004: 105)
- Bryoria pseudofuscenscens (Gyeln.) Brodo & D. Hawksw. - Thomson (1984: 63)
- Buellia alboatra (Hoffm.) Th. Fr. - Douglas (1974: 584), Thomson (1997: 127)
- Buellia disciformis (Fr.) Mudd - Douglas (1974: 584), Thomson (1997: 129)
Buellia disciformis var. saxicola - Eyerdam (1960: 107)
- Buellia epigaea (Hoffm.) Tuck. - Douglas (1974: 584)
- Buellia geophila (Flörke ex Sommerf.) Lynge - Thomson (1997: 133)
- Buellia papillata (Sommerf.) Tuck. - Douglas (1974: 584), Thomson (1997: 136)
- Buellia zahlbrucknerii J. Stein - Douglas (1974: 584)
- Calicium abietinum Pers. - Thomson (1997: 143)
- Calicium viride Pers. - Douglas (1974: 584), Thomson (1997: 146)
- Caloplaca atrosanguinea (Merr.) Lamb. - Douglas (1974: 584)
- Caloplaca cerina (Ehrh.) Th. Fr. - Douglas (1974: 584), Thomson (1997: 154)
- Caloplaca citrina (Hoffm.) Th. Fr. - Thomson (1997: 155)
- Caloplaca crenularia (With.) J. R. Laundon - Thomson (1997: 157)
- Caloplaca exsecuta (Nyl.) Dalla Torre & Sarnth. - Thomson (1997: 160)
- Caloplaca ferruginea (Huds.) Th. Fr. - Douglas (1974: 584)
- Caloplaca fraudans (Th. Fr.) Oliv. - Thomson (1997: 162)
- Caloplaca holocarpa (Hoffm.) Wade - Douglas (1974: 585), Thomson (1997: 164)
- Caloplaca jungermanniae (Vahl) Th. Fr. - Herre (1917:), Douglas (1974: 585), Thomson (1997: 166)
- Caloplaca saxicola (Hoffm.) Nordin - Douglas (1974: 585 sub Caloplaca murorum)
- Caloplaca scopularis (Nyl.) Lettau - Thomson (1997: 168)
- Caloplaca stillicidiorum (Vahl) Lynge - Douglas (1974: 585), Thomson (1997: 172)
- Caloplaca tetraspora (Nyl.) Oliv. - Thomson (1997: 172)
- Caloplaca tiroliensis Zahlbr. - Thomson (1997: 173)
- Caloplaca tominii Savicz - Thomson (1997: 173)
- Candelariella aurella (Hoffm.) Zahlbr. - Herre (1917:), Douglas (1974: 585), Thomson (1997: 182)
- Candelariella terrigena Räsänen - Douglas (1974: 585), Thomson (1997: 187)
- Candelariella vitellina (Hoffm.) Müll. Arg. - Thomson (1997: 189)
Catillaria franciscana (Tuck.) Herre - Eyerdam (1960: 107)
- Catillaria glauconigricans (Tuck.) Hasse - Thomson (1997: 197)
- Catinaria atropurpurea (Schaer.) Vezda & Poelt - Thomson (1997: 201)
- Cetraria aculeata (Schreb.) xxx - Imshaug (1957: ), Douglas (1974: 586 as Cornicularia aculeata)
- Cetraria chlorophylla (Willd.) Vain. - Herre (1917:), Douglas (1974: 585), Thomson (1984: 73)
- Cetraria ciliaris Ach. - Douglas (1974: 585)
- Cetraria commixta (Nyl.) Th. Fr. - Imshaugh (1957:), Douglas (1974: 585), Thomson (1984: 75)
- Cetraria cucullata (Bell.) Ach. - Imshaugh (1957), Douglas (1974: 585), Thomson (1984: 76)
- Cetraria ericetorum Opiz - Douglas (1974: 585), Thomson (1984: 79)
- Cetraria hepatizon (Ach.) Vain. - Imshaugh (1957:), Douglas (1974: 585), Thomson (1984: 82)
- Cetraria idahoensis Essl. - Esslinger (1971: 366 Protolog), Douglas (1974: 585 as Cetraria idahoensis) Type in DUKE
- Cetraria islandica (L.) Ach. - Herre (1917:), Howard (1950:), Imshaugh (1957:), Douglas (1974: 585), Thomson (1984: 84)
- vulpicida juniperina (L.) xxx - Howard (1950 sub Cetraria juniperina), Esslinger (1973 sub Cetraria juniperina), Douglas (1974: 585 sub Cetraria juniperina)
- Cetraria laevigata Rass. - Thomson (1984: 88)
- Cetraria nivalis (L.) Ach. - Imshaugh (1957:), Douglas (1974: 585), Thomson (1984: 92)
- Cetraria pinastri (Scop.) S. Gray - Imshaugh (1957: as Cetraria pinastri), Thomson (1984: 93 as Cetraria pinastri)
- Cetraria platyphylla (Tuck.) Herre - Herre (1917), Douglas (1974: 585)
- Cetraria subalpina Imshaugh - Douglas (1974: 585)
- Cetrelia cetrarioides (Del. ex Duby) W. L. Culb. & C. Culb. - Eyerdam (1960:), Culberson & Culberson (1968), Douglas (1974: 585), Thell et al. (1998: 309) DNA: ITS
- Cladonia anomaea (Ach.) Ahti & P. James - Thomson (1984: 109)
- Cladonia arbuscula (Wallr.) Rabenh. - Herre (1917: ), Douglas (1974: 585 sub Cladina arbuscula), Thomson (1984: 110)
- Cladonia bacillaris (Ach.) Nyl. - Herre (1917:), Douglas (1974: 585), Thomson (1984: 111)
- Cladonia bellidiflora (Ach.) Schaer. - Herre (1917), Eyerdam (1960), Douglas (1974: 585), Thomson (1984: 113)
Cladonia bellidiflora f. coccocephala - Eyerdam (1960: 107)
Cladonia bellidiflora f. hookeri - Eyerdam (1960: 107)
- Cladonia capitata (Michx.) Spreng. - Eyerdam (1960), Douglas (1974: 585)
Cladonia capitata f. microcarpa Evans - Eyerdam (1960: 107)
- Cladonia cariosa (Ach.) Spreng. - Howard (1950), Douglas (1974: 585), Thomson (1984: 116)
- Cladonia carneola (Fr.) Fr. - Douglas (1974: 585)
- Cladonia cenotea (Ach.) Schaer. - Thomson (1984: 118)
- Cladonia chlorophaea (Flörke ex. Sommerf.) Spreng. - Howard (1950), Eyerdam (1960: 107 as Cladonia chlorophaea f. simplex), Douglas (1974: 585), Thomson (1984: 119)
- Cladonia coccifera (L.) Willd. - Douglas (1974: 586), Thomson (1984: 121)
- Cladonia coniocraea (Flörke) Spreng. - Howard (1950), Eyerdam (1960: 107 as Cladonia coniocraea f. ceratodes, f. finkii, f. truncata), Douglas (1974: 586), Thomson (1984: 122)
- Cladonia cornuta (L.) Hoffm. - Eyerdam (1960: 108), Douglas (1974: 586), Thomson (1984: 124)
Cladonia cornutoradiata (Coem.) Vain. - Eyerdam (1960: 108)
- Cladonia cryptochlorophaea Asah. - Thomson (1984: 126)
- Cladonia cyanipes (Somm.) Nyl. - Thomson (1984: 127)
- Cladonia deformis (L.) Hoffm. - Douglas (1974: 586)
Cladonia degenerans f. phyllophora - Eyerdam (1960: 108)
- Cladonia digitata (L.) Hoffm. - Thomson (1984: 131)
- Cladonia ecmocyna Leight. - Douglas (1974: 586), Thomson (1984: 132)
- Cladonia fimbriata (L.) Fr. - Douglas (1974: 586), Thomson (1984: 133)
- Cladonia floerkeana (Fr.) Flörke - Eyerdam (1960: 107), Douglas (1974: 586)
- Cladonia furcata (Huds.) Schrad. - Eyerdam (1960: ), Douglas (1974: 586)
Cladonia furcata var. racemosa - Eyerdam (1960: 108)
- Cladonia gonecha (Ach.) Asah. - Douglas (1974: 586)
- Cladonia gracilis subsp. turbinata (Ach.) Ahti - Thomson (1984: 136)
- Cladonia gracilis (L.) Willd. var. gracilis - Herre (1917: ), Eyerdam (1960: ), Douglas (1974: 586), Thomson (1984: 137)
Cladonia gracilis var. dilatata - Eyerdam (1960: 108)
- Cladonia grayi Merrl. - Thomson (1984: 139)
- Cladonia hookeri Tuck. - Herre (1943: ), Douglas (1974: 586)
- Cladonia lepidota Nyl. - Eyerdam (1960: 108 as Cladonia lepidota var. stricta f. pterophora), Douglas (1974: 586)
- Cladonia macilenta Hoffm. - Herre (1917: ), Eyerdam (1960: 108 as Cladonia macilenta f. granulosa and f. stryracella)
- Cladonia macrophyllodes Nyl. - Thomson (1984: 143)
- Cladonia major (Hag.) Sandst. - Thomson (1984: 144)
- Cladonia merochlorophaea Asah. - Thomson (1984: 143)
- Cladonia mitis Sandst. - Imshaugh (1957:), Douglas (1974: 585 sub Cladina mitis), Thomson (1984: 148)
- Cladonia multiformis Merr. - Douglas (1974: 586), Thomson (1984: 149)
Cladonia multiformis f. subascypha - Eyerdam (1960: 108)
Cladonia ochrochlora Flörke - Eyerdam (1960: 108)
- Cladonia phyllophora Ehrh. ex Hoffm. - Eyerdam (1960: ), Douglas (1974: 586), Thomson (1984: 153)
- Cladonia pityrea (Flörke) Fr. - Eyerdam (1960: 108 as Cladonia pityrea f. cornuta, f. squamulifera and f. zwackhii), Douglas (1974: 586)
- Cladonia pyxidata (L.) Hoffm. - Herre (1917: ), Imshaug (1957: ), Eyerdam (1960: 108 as Cladonia pyxidata var. neglecta), Douglas (1974: 586), Thomson (1984: 158)
- Cladonia rangiferina (L.) F. H. Wigg. - Herre (1917:), Douglas (1974: 585 sub Cladina rangiferina), Thomson (1984: 159)
Cladonia scabriuscula f. surrecta - Eyerdam (1960: 108)
- Cladonia squamosa (Scop.) Hoffm. - Herre (1917: ), Douglas (1974: 586), Thomson (1984: 161)
- Cladonia stricta (Nyl.) Nyl. - Thomson (1984: 164)
- Cladonia subcervicornis (Vain.) Du Rietz - Thomson (1984: 165)
- Cladonia subsquamosa (Nyl.) Vain. - Howard (1950: ), Douglas (1974: 586)
- Cladonia subulata (L.) F. H. Wigg. - Eyerdam (1960: ), Douglas (1974: 586), Thomson (1984: 168)
- Cladonia turgida Ehrh. ex Hoffm. - Eyerdam (1960: 108), Thomson (1984: 172)
- Cladonia uncialis (L.) F. H. Wigg. - Thomson (1984: 173)
- Cladonia verticillata (Hoffm.) Schaer. - Herre (1917: ), Douglas (1974: 586), Thomson (1984: 174)
- Coniocybe furfuracea (L.) Ach. - Eyerdam (1960: 108), Thomson (1997: 210)
- Cornicularia aculeata (Schreb.) Ach. - Thomson (1984: 198)
- Cornicularia normoerica (Gunn.) DR. - Imshaug (1957: ), Douglas (1974: 586), Thomson (1984: 201)
- Cyphelium inquinans (Sm. in Sm. & Sow.) Trevisan - Herre (1917: ), Douglas (1974: 586), Thomson (1997: 212)
- Cyphelium ocellatum (Körb.) Trevisan - Thomson (1997: 213)
- Cyphelium tigillare (Ach.) Ach. - Thomson (1997: 214)
- Dactylina arctica (Richards.) Nyl. - Imshaug (1957), Douglas (1974: 586), Thomson (1984: 203)
- Dermatocarpon fluviatile (Web.) Th. Fr. - Douglas (1974: 586), Thomson (1984: 213)
- Dermatocarpon intestiniforme (Körb.) Hasse - Thomson (1984: 216)
- Dermatocarpon meiophyllizum Vain. - Glavich & Geiser (2004: 139)
- Dermatocarpon miniatum (L.) Mann. - Howard (1950), Douglas (1974: 586), Thomson (1984: 219)
- Diploschistes actinostomus (Pers.) Zahlbr. - Herre (1943), Douglas (1974: 586)
- Diploschistes muscorum (Scop.) R. Sant. - Thomson (1997: 218)
- Diploschistes scruposus (Schreber) Norman - Douglas (1974: 586), Thomson (1997: 218)
- Erioderma sorediatum D. J. Galloway & P. M. Jörg. - Geiser et al. (2004: 106)
- Euopsis granatina (Sommerf.) Nyl. - Thomson (1997: 223)
- Evernia prunastri (L.) Ach. - Herre (1917: ), Howard (1950: ), Douglas (1974: 586)
- Fellhanera bouteillei (Desm.) Vezda - Douglas (1974: 585 sub Catillaria bouteilei)
- Fisturiella roesleri (Hoechst. ex Schaer.) Bowler & Rundel - Thomson (1984: 233)
- Graphis scripta (L.) Ach. - Howard (1950), Douglas (1974: 586)
- Gyalecta jenensis (Batsch) Zahlbr. - Thomson (1997: 241)
- Haematomma lapponicum Räs. - Douglas (1974: 586)
- Heppia lutosa (Ach.) Nyl. - Herre (1917: ), Douglas (1974: 586)
- Heterodermia leucomela (L.) Poelt - Geiser et al. (2004: 106)
- Hymenelia lacustris (With.) M. Choisy - Thomson (1997: 245)
- Hypocenomyce friesii (Ach. in Lilj.) James & Schneider - Thomson (1997: 247)
- Hypocenomyce scalaris (Ach. ex Lilj.) M. Choisy - Thomson (1997: 248)
- Hypogymnia austerodes Nyl. - Thomson (1984: 237)
- Hypogymnia enteromorpha (Ach.) Nyl. - Herre (1917: ), Douglas (1974: 586)
- Hypogymnia oroacrctica Krog - Thomson (1984: 239)
- Hypogymnia physodes (L.) Nyl. - Herre (1917: ), Douglas (1974: 587), Thomson (1984: 241)
- Hypogymnia vittata (Ach.) Gas. - Howard (1950), Douglas (1974: 587), Thomson (1984: 243)
- Icmadophila ericetorum (L.) Zahlbr. - Herre (1917: ), Howard (1950: ), Douglas (1974: 587), Thomson (1997: 249)
- Lecania dimera (Nyl.) Th. Fr. - Herre (1917: ), Douglas (1974: 587)
- Lecanora alpina Somm. - Herre (1917: ), Douglas (1974: 587)
- Lecanora badia (Hoffm.) Ach. - Thomson (1997: 269)
- Lecanora caesiocinerea Nyl. - Douglas (1974: 587)
- Lecanora calcarea (L.) Somm. - Herre (1943: ), Howard (1950: ), Douglas (1974: 587)
- Lecanora cenisia Ach. - Douglas (1974: 587), Thomson (1997: 272)
- Lecanora chlarotera Nyl. - Thomson (1997: 273)
Lecanora cinerea var. microspora Fink - Eyerdam (1960: 108)
- Lecanora cinereofusca H. Magn. - Douglas (1974: 587)
- Lecanora circumborealis Brodo & Vitik. - Thomson (1997: 274)
- Lecanora coilocarpa (Ach.) Nyl. - Herre (1917: ), Douglas (1974: 587)
Lecanora conizaea - Eyerdam (1960: 108)
Lecanora contorta (Hoffm.) Stein - Eyerdam (1960: 108)
Lecanora diffracta Ach. - Eyerdam (1960: 108)
- Lecanora dispersa (Pers.) Sommerf. - Thomson (1997: 278)
- Lecanora epibryon (Ach.) Ach. - Douglas (1974: 587)
- Lecanora expallens Ach. - Thomson (1997: 281)
- Lecanora frustulosa (Dicks.) Ach. - Herre (1917), Douglas (1974: 587)
- Lecanora gibbosula H. Magn. - Herre (1917: ), Howard (1950: ), Douglas (1974: 587)
- Lecanora grantii H. Magn. - Thomson (1997: 284)
- Lecanora hagenii (Ach.) Ach. - Herre (1917: ), Howard (1950: ), Douglas (1974: 587), Thomson (1997:286)
- Lecanora laevata (Ach.) Nyl. - Herre (1943), Douglas (1974: 587)
- Lecanora marginata (Schaer.) Hertel & Rambold- Thomson (1997: 291)
Lecanora melaena (Hedl.) Fink - Eyerdam (1960: 108)
- Lecanora muralis (Schreb.) Rabenh. - Howard (1950: ), Douglas (1974: 587), Thomson (1997: 295)
- Lecanora orae-frigidae R. Sant. - Thomson (1997: 297)
- Lecanora pacifica Tuck. - Herre (1917: ), Douglas (1974: 587)
- Lecanora polytropa (Ehrh. in Hoffm.) Rabenh. - Herre (1917: ), Douglas (1974: 587), Thomson (1997: 299)
- Lecanora pulicaris - Thomson (1997: 301)
- Lecanora rupicola (L.) Zahlbr. - Douglas (1974: 587), Thomson (1997: 303)
- Lecanora subfusca (L.) Ach. - Herre (1917: ), Douglas (1974: 587)
- Lecanora subrugosa Nyl. - Thomson (1997: 308)
- Lecanora supertegens (Arnold) Zahlbr. - Douglas (1974: 587)
- Lecanora symmicta (Ach.) Ach. - Thomson (1997: 309)
- Lecanora umbrosa Degel. - Anderson (1974: 44)
- Lecanora varia (Hoffm.) Ach. - Herre (1917), Douglas (1974: 587), Thomson (1997: 311)
- Lecidea atrobrunnea (Ramond ex Lam. & DC.) Schaer. - Douglas (1974: 587), Thomson (1997: 327)
- Lecidea auriculata Th. Fr. - Howard (1950: ), Douglas (1974: 587), Thomson (1997: 329)
- Lecidea berengeriana (A. Massal.) Th. Fr. - Douglas (1974: 587), Thomson (1997: 331)
- Lecidea caesioatra Schaer. - Herre (1917: ), Howard (1950: )
Lecidea cascadensis H. Magn. - Eyerdam (1960: 108)
- Lecidea cineratra Zahlbr. - Douglas (1974: 587)
- Lecidea cinnabarina Sommerf. - Thomson (1997: 336)
Lecidea coarctica (Sm.) Nyl. - Eyerdam (1960: 109)
- Lecidea confluens (W. A. Weber) Ach. - Douglas (1974: 587), Thomson (1997: 339)
- Lecidea cyathoides (Ach.) Ach. - Herre (1917: ), Douglas (1974: 588)
- Lecidea furvonigrans (Tuck.) Zahlbr. - Douglas (1974: 588)
- Lecidea fuscescens Somm. - Douglas (1974: 588)
- Lecidea fuscoatra (L.) Ach. - Thomson (1997: 347)
- Lecidea glaucophaea Körb. - Douglas (1974: 588)
- Lecidea globifera Ach. - Howard (1950: ), Douglas (1974: 588)
- Lecidea glomerulosa (DC.) Steud. - Douglas (1974: 588)
- Lecidea granulosa (Ehrh.) Ach. - Howard (1950: )
- Lecidea hypnorum Lib. - Thomson (1997: 351)
- Lecidea lactea Flörke ex Schaerer - Thomson (1997: 355)
- Lecidea lapicida (Ach.) Ach. - Howard (1950: ), Douglas (1974: 588), Thomson (1997: 357)
- Lecidea leucothallina Arnold - Thomson (1997: 360)
- Lecidea lithophila (Ach.) Ach. - Thomson (1997: 362)
- Lecidea lurida (Dill.) Ach. - Howard (1950: ), Douglas (1974: 588)
- Lecidea marginata Schaer. - Herre (1943: ), Douglas (1974: 588)
- Lecidea paddensis (Tuck.) Zahlbr. - Douglas (1974: 588)
- Lecidea paupercula Th. Fr. - Thomson (1997: 369)
- Lecidea plana Lahm ex Körb. - Douglas (1974: 588)
Lecidea platycarpa Ach. - Eyerdam (1960: 109)
- Lecidea rubiformis (Wahlenb. ex Ach.) Wahlenb. - Herre (1917: ), Douglas (1974: 588)
- Lecidea rufonigra (Tuck.) Nyl. - Douglas (1974: 588)
- Lecidea sanguineoatra (Wulf.) Ach. - Douglas (1974: 588)
- Lecidea tessellata Flörke - Herre (1917: ), Howard (1950: ), Douglas (1974: 588), Thomson (1997: 384)
- Lecidea tornoensis Nyl. - Douglas (1974: 588), Thomson (1997: 387)
- Lecidea uliginosa (Schrad.) Ach. - Douglas (1974: 588)
- Lecidea vernalis (L.) Ach. - Thomson (1997: 389)
- Lecidella carpathica Körb. - Thomson (1997: 395)
- Lecidella elaeochroma (Ach.) Hazslin. - Herre (1943: ), Douglas (1974: 588), Thomson (1997: 396)
- Lecidella euphorea (Flörke) Hertel - Thomson (1997: 398)
- Lecidella stigmatea (Ach.) Hertel & Leuck. - Douglas (1974: 588), Thomson (1997: 402)
- Lecidella wulfenii (Hepp) Körb. - Thomson (1997: 403)
- Lecidoma demissum (Rutstr.) Schneider & Hertel - Douglas (1974: 588 as Lecidea demissa), Thomson (1997: 405)
- Leioderma sorediatum D. J. Galloway & P. M. Jørg. - Geiser et al. (2004: 106)
- Lepraria membranacea (Dicks.) Vain. - Douglas (1974: 588)
- Lepraria neglecta (Nyl.) Lett. - Douglas (1974: 588)
- Leprocaulon subalbicans (J. M. Lamb) J. M. Lamb & Ward - Thomson (1984: 250)
- Leptochidium albociliatum (Desm.) M. Choisy - Thomson (1984: 252)
- Leptogium brebissonii Mont. - Geiser et al. (2004: 107)
- Leptogium lichenoides (L.) Zahlbr. - Howard (1950: ), Douglas (1974: 588), Thomson (1984: 257)
- Leptogium minutissimum (Dicks.) Fr. - Thomson (1984: 259)
- Leptogium palmatum (Huds.) Mont. in Webb. & Berth.- Thomson (1984: 260)
- Leptogium rivale Tuck. - Glavich & Geiser (2007: 8)
- Leptogium saturninum (Dicks.) Nyl. Thomson (1984: 262)
- Leptogium sinuatum (Huds.) Mass. - Thomson (1984: 263)
- Leptogium subaridum P. M. Jørg. & Goward - Aragón et al. (2004: 165)
- Leptogium tenuissimum (Dicks.) Fr. - Herre (1917: ), Douglas (1974: 588)
- Letharia vulpina (L.) Hue - Herre (1917: ), Douglas (1974: 588)
- Lichenoconium christiansenii M. S. Cole & D. Hawksw. - Cole & Hawksworth (2004: 1 Protologue) Type in "K(M)"
- Lobaria hallii (Tuck.) Zahlbr. - Thomson (1984: 266)
- Lobaria linita (Ach.) Rabenh. - Douglas (1974: 588), Thomson (1984: 269)
- Lobaria oregana (Tuck.) Müll. Arg. - Herre (1917: ), Howard (1950: ), Douglas (1974: 588)
- Lobaria pulmonaria (L.) Hoffm. - Herre (1917: ), Douglas (1974: 588)
- Lobaria scrobiculata (Scop.) DC. - Herre (1943: ), Douglas (1974: 588), Thomson (1984: 271)
- Lopadium pezizoideum (Ach.) Körb. - Thomson (1997: 411)
- Massalongia carnosa (Dicks.) Körb. - Herre (1917: ), Douglas (1974: 588), Thomson (1984: 274)
- Melanohalea infumata (Nyl.) O. Blanco et al. - Imshaug (1957: as Parmelia infumata), Douglas (1974: 589 as Parmelia infumata), Thomson (1984: 304 as Parmelia infumata)
- Menegazzia terebrata (Hoffm.) A. Massal. - Howard (1955: ), Douglas (1974: 588)
- Micarea denigrata (Fr.) Hedl. - Thomson (1997: 415)
- Micarea xanthonica Coppins & Tønsberg - Coppins & Tønsberg (2001: 93 Protolog) Type in Bergen, Norway (BG)
- Mycobilimbia sabuletorum (Schreb.) Hafellner - Thomson (1997: 422)
- Mycoblastus affinis (Schaer.) Schauer- Thomson (1997: 424)
- Mycoblastus sanguinarius (L.) Norman - Douglas (1974: 588), Thomson (1997: 426)
- Nephroma bellum (Spreng.) Tuck. - Wetmore (1960: ), Douglas (1974: 588), Thomson (1984: 278)
- Nephroma helveticum Ach. - Herre (1917: ), Douglas (1974: 588)
- Nephroma laevigatum Ach. - Herre (1917: ), Douglas (1974: 588)
- Nephroma parile (Ach.) Ach. - Wetmore (1960: ), Douglas (1974: 588), Thomson (1984: 282)
- Nephroma resupinatum (L.) Ach. - Wetmore (1960: ), Douglas (1974: 588), Thomson (1984: 283)
Nephromopsis californica Gyeln. - Eyerdam (1960: 109)
- Neuropogon lambii Imshaug - Weber (1973: ), Douglas (1974: 588)
- Niebla cephalota (Tuck.) Rundel & Bowler - Geiser et al. (2004: 107)
- Nodobryoria abbreviata - Cole & Hawksworth (2004: 1)
- Nodobryoria oregona (Tuck.) Common & Brodo - Douglas (1974: 584 sub Alectoria oregona)
- Ochrolechia androgyna (Hoffm.) Arnold - Douglas (1974: 589), Thomson (1997: 430)
- Ochrolechia inaequatula (Nyl.) Zahlbr. - Thomson (1997: 434)
- Ochrolechia oregonensis H. Magn. - Eyerdam (1960: 109), Douglas (1974: 589)
- Ochrolechia pallescens (L.) A. Massal. - Herre (1943: ), Douglas (1974: 589)
- Ochrolechia parella (L.) A. Massal. - Douglas (1974: 589)
- Ochrolechia tartarea (L.) A. Massal. - Herre (1917: ), Howard (1970: ), Douglas (1974: 589)
- Ochrolechia upsaliensis (L.) A. Massal. - Douglas (1974: 589), Thomson (1997: 436)
- Omphalodiscus decussatus (Vill.) Schol.- Imshaug (1950: ), Douglas (1974: 589), Thomson (1984: 288)
- Omphalodiscus krascheninnikovii (Sav.) Schol. - Thomson (1984: 289)
- Omphalodiscus virginis (Schaer.) Schol. - Imshaug (1957: ), Douglas (1974: 589), Thomson (1984: 290)
- Opegrapha pulicaris (Hoffm.) Schrad. - Herre (1917: ), Douglas (1974: 589)
- Ophioparma lapponica (Räsänen) Hafellner & Rogers - Thomson (1997: 440)
- Orphniospora moriopsis (A. Massal.) D. Hawksw. - Thomson (1997: 441)
- Pachyospora verrucosa (Ach.) A. Massal. - Thomson (1997: 443)
- Pannaria pezizoides (Web.) Trev. - Thomson (1984: 294)
- Pannaria rubiginosa (Ach.) Bory - Howard (1950: ), Douglas (1974: 589), Geiser et al. (2004: 107)
- Parmelia alpicola Th. Fr. - Imshaug (1957 as Parmelia alpicola), Douglas (1974: 589 as Parmelia alpicola), Thomson (1984: 299 sub Parmelia alpicola)
Parmelia cetrarioides Del. - Eyerdam (1960: 109)
- Parmelia disjuncta Erichs. - Eyerdam (1960: 109), Thomson (1984: 299 sub Parmelia disjuncta)
- Parmelia elegantula (Zahlbr.) Szat. - Thomson (1984: 300 sub Parmelia elegantula)
Parmelia exasperata - Eyerdam (1960: 109)
- Melanelia exasperatula (Nyl.) xxx - Thomson (1984: 300 sub Parmelia exasperatula)
Parmelia fuliginosa - Eyerdam (1960: 109)
- Melanelia glabratula (Lamy) Nyl. - Thomson (1984: 303 sub Parmelia glabratula)
Parmelia laciniatula - Eyerdam (1960: 109 as Parmelia laciniatula)
- Parmelia multispora Schneid. - Howard (1950: ), Douglas (1974: 589 as Parmelia multispora)
- Parmelia omphalodes (L.) Ach. - Thomson (1984: 308)
- Parmelia panniformis (Nyl.) Vain. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 309)
- Parmelia perlata (Huds.) Ach. - Herre (1917), Douglas (1974: 589)
- Parmelia saxatilis (L.) Ach. - Howard (1950: ), Imshaug (1957), Douglas (1974: 589), Thomson (1984: 310)
- Parmelia sorediosa Almb. - Thomson (1984: 312 sub Parmelia sorediosa)
- Parmelia stygia var. contrubata (Arn.) Dalla Torre & Sarnth. - Thomson (1984: 315)
- Melanelia subaurifera Nyl. - Thomson (1984: 316 sub Parmelia subaurifera)
- Parmelia substygia Räs. - Thomson (1984: 317 sub Parmelia substygia)
- Parmelia sulcata Tayl. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 318)
- Parmeliella cyanolepra (Tuck.) Herre - Herre (1917: ), Douglas (1974: 589)
- Parmeliella praetermissa (Nyl.) P. James - Howard (1950: ), Douglas (1974: 589)
- Parmeliella tryptophylla (Ach.) Müll. - Thomson (1984: 321)
- Parmeliopsis ambigua (Wulf.) Nyl. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 325)
- Parmeliopsis hyperopta (Ach.) Arn. - Herre (1943: ), Douglas (1974: 589), Thomson (1984: 326)
- Peltigera aphthosa (L.) Willd. - Herre (1917: ), Thomson (1950: ), Howard (1950: ), Eyerdam (1960: ), Douglas (1974: 589), Thomson (1984: 329)
- Peltigera aphthosa var. leucophlebia Nyl. - Thomson (1984: 330)
Peltigera aphthosa var. variolosa - Eyerdam (1960: 109)
- Peltigera canina (L.) Willd. - Herre (1917: ), Howard (1950: ), Douglas (1974: 589)
- Peltigera canina (L.) Willd. f. sorediata Schaer. - Thomson (1984: 332)
- Peltigera canina (L.) Willd. var. rufescesns (Weis.) Mudd - Thomson (1984: 333)
Peltigera canina f. leucorrhiza Flörke - Eyerdam (1960: 109)
- Peltigera collina (Ach.) Schrad. - Thomson (1950: ), Douglas (1974: 589), Thomson (1984: 334)
- Peltigera horizontalis (Huds.) Baumg. - Thomson (1984: 337)
- Peltigera lepidophora (Nyl.) Vain. - Imshaug (1950: ), Douglas (1974: 589), Thomson (1984: 338)
- Peltigera malacea (Ach.) Funck. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 339)
- Peltigera membranacea (Ach.) Nyl. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 340)
- Peltigera polydactyla (Neck.) Hoffm. - Herre (1917: ), Thomson (1950: ), Imshaug (1957: ), Douglas (1974: 589), Thomson (1984: 343)
- Peltigera scabrosa Th. Fr. - Thomson (1984: 344)
- Peltigera spuria - Herre (1917: ), Thomson (1950: ), Douglas (1974: 589)
- Peltigera venosa (L.) Baumg. - Herre (1917: ), Howard (1950), Douglas (1974: 589), Thomson (1984: 345)
- Pertusaria amara (Ach.) Nyl. - Herre (1917: ), Douglas (1974: 589)
- Pertusaria carneopallida (Nyl.) Anzi ex Nyl. - Thomson (1997: 451)
- Pertusaria glaucomela (Tuck.) Nyl. - Douglas (1974: 589)
- Pertusaria leioplaca (Ach.) DC. - Herre (1917: ), Douglas (1974: 589)
- Pertusaria multipuncta (Turn.) Nyl. - Herre (1917: ), Douglas (1974: 589)
- Pertusaria pertusa (L.) Tuck. - Herre (1917: ), Douglas (1974: 589)
Pertusaria pocillum - Eyerdam (1960: 109)
- Pertusaria sommerfeltii (Flörke ex Sommerf.) Fr. - Thomson (1997: 461)
- Phaeophyscia endococcinea (Körb.) Moberg - Thomson (1984: 348)
- Phaeophyscia sciastra (Ach.) Moberg - Thomson (1984: 349)
- Physcia adscendens (Fr.) Oliv. - Thomson (1984: 352)
- Physcia aipolia (Humb.) Fürnrohr - Herre (1917: ), Thomson (1963), Douglas (1974: 589), Thomson (1984: 353)
- Physcia caesia (Hoffm.) Fürnrohr - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 354)
- Physcia cascadensis H. Magn. - Thomson (1963: ), Douglas (1974: 590)
- Physcia dubia (Hoffm.) Lettau - Imshaug (1957: ), Thomson (1963: ), Douglas (1974: 590), Thomson (1984: 355)
- Physcia phaea (Tuck.) Thoms. - Thomson (1984: 356)
- Physcia stellaris (L.) Nyl. - Howard (1950: ), Douglas (1974: 590)
Physcia tenella - Eyerdam (1960: 109)
- Physcia teretiuscula (Ach.) Lynge - Imshaug (1957: ), Thomson (1963: ), Douglas (1974: 590)
- Physcia tribacea (Ach.) Nyl. - Howard (1950: ), Douglas (1974: 590)
- Physconia detersa (Nyl.) Poelt - Thomson (1984: 359)
- Physconia muscigena (Ach.) Poelt - Imshaug (1957: ), Thomson (1963: ), Douglas (1974: 590), Thomson (1984: 360)
- Physconia pulverulenta (Schreb.) Poelt - Herre (1917: ), Howard (1950: ), Douglas (1974: 590)
- Pilophoron acicularis (Ach.) Nyl. - Eyerdam (1960: 109), Douglas (1974: 590)
- Pilophoron cereolus (Ach.) Th. Fr. - Herre (1917: ), Howard (1950: ), Howard (1955: ), Douglas (1974: 590)
- Pilophoron clavatu Th. Fr. - Herre (1917: ), Douglas (1974: 590)
- Placopsis gelida (L.) Lindsay - Thomson (1997: 472)
- Placynthiella uliginosa (Schrad.) Coppins & James - Thomson (1997: 475)
- Platismatia glauca (L.) W. Culb. & C. Culb. - Herre (1917: ), Howard (1950: ), Howard (1955), Douglas (1974: 590), Thomson (1984: 368)
- Platismatia herrei (Imshaug) W. Culb. & C. Culb. - Herre (1917: ), Howard (1950: ), Culberson & Culberson (1968: ), Douglas (1974: 590)
- Platismatia lacunosa (Ach.) W. Culb. & C. Culb. - Herre (1917: ), Douglas (1974: 590)
- Platismatia norvegica (Lynge) W. Culb. & C. Culb. - Douglas (1974: 590), Thell et al. (1998: 309) DNA: ITS
- Platismatia stenophylla xxx - Thell et al. (1998: 309) DNA: ITS
- Placopsis gelida (L.) Linds. - Herre (1917: ), Douglas (1974: 590)
- Pleopsidium chlorophanum (Wahlenb. ex Ach.) - Douglas (1974: 584 sub Acarospora chlorophana)
- Polychidium muscicola (Sw.) Gray - Thomson (1984: 370)
- Polysporina simplex (Davis) Vezda - Thomson (1997: 486)
- Porpidia albocaerulescens (Wulf.) Ach. - Howard (1950: as Lecidea albocaerulescens), Douglas (1974: 587 as Lecidea albocaerulescens)
- Porpidia crustulata (Ach.) xxx - Douglas (1974: 587 as Lecidea crustulata)
- Porpidia grisea Gowan - Thomson (1997: 493)
- Porpidia macrocarpa (DC.) Steud. - Eyerdam (1960: as Lecidea macrocarpa), Douglas (1974: 588 as Lecidea macrocarpa)
- Porpidia speirea (Ach.) Kremp. - Herre (1943: ), Douglas (1974: 588 as Lecidea speirea), Thomson (1997: 497)
- Porpidia thomsonii Gowan - Thomson (1997: 498)
- Protothelenella sphinctrinoides (Nyl.) Mayrh. & Poelt - Thomson (1997: 505)
- Pseudephebe minuscula (Nyl. ex Arnold) Brodo & D. Hawksw. - Douglas (1974: 584 sub Alectoria minuscula), Thomson (1984: 373)
- Pseudephebe pubescens (L.) M. Choisy - Douglas (1974: 584 sub Alectoria pubescens), Thomson (1984: 374)
- Pseudocyphellaria anthraspis (Ach.) H. Magn. - Herre (1917: ), Douglas (1974: 590)
- Pseudocyphellaria perpetua McCune & Miadlikowska - Geiser et al. (2004: 107)
- Psora globifera (Ach.) A. Massal. - Thomson (1997: 508)
- Psora lurida(Ach.) DC. - Thomson (1997: 509)
- Psora nipponica (Zahlbr.) Schneider - Thomson (1997: 510)
- Psoroma hypnorum (Vahl) Gray - Douglas (1974: 590), Thomson (1984: 375)
- Pyrrhospora gowardiana Spribille & Hauck - Spribille & Hauck (2003: 560)
- Pyrrhospora quernea (Dickson) Körb. - Geiser et al. (2004: 108)
- Ramalina farinacea (L.) Ach. - Douglas (1974: 590)
- Ramalina geniculata Hook. f. & Tayl. - Howard (1955), Douglas (1974: 590)
- Ramalina inflata Hook. f. & Tayl. - Herre (1917:), Douglas (1974: 590)
Ramalina leptocarpha var. sorediata - Eyerdam (1960: 109)
- Ramalina pollinaria (Westr.) Ach. - Geiser et al. (2004: 109)
- Rhizocarpon badioatrum (Flörke ex Sprengel) Th. Fr. - Thomson (1997: 524)
- Rhizocarpon bolanderi (Tuck.) Herre - Thomson (1997: 526)
- Rhizocarpon cinereovirens (Müll. Arg.) Vain. - Thomson (1997: 528)
- Rhizocarpon concentricum (Davis) Beltram. - Thomson (1997: 529)
- Rhizocarpon copelandii (Körb.) Th. Fr. - Thomson (1997: 531)
- Rhizocarpon disporum (Naeg. ex Hepp) Müll. Arg. - Herre (1917: ), Howard (1950: ), Douglas (1974: 590)
- Rhizocarpon distinctum Th. Fr. - Herre (1943: ), Douglas (1974: 590)
- Rhizocarpon geminatum Körb. - Thomson (1997: 537)
- Rhizocarpon geographicum (L.) DC. - Douglas (1974: 590), Thomson (1997: 538)
- Rhizocarpon grande (Flörke ex Flotow) Arnold - Thomson (1997: 539)
- Rhizocarpon hochstetteri (Körb.) Vain. - Herre (1943: ), Douglas (1974: 590), Thomson (1997: 540)
- Rhizocarpon jemtlandicum Malme - Douglas (1974: 590), Thomson (1997: 542)
- Rhizocarpon macrosporum Räsänen - Douglas (1974: 590), Thomson (1997: 543)
- Rhizocarpon obscuratum (Ach.) A. Massal. - Douglas (1974: 590), Thomson (1997: 545)
- Rhizocarpon polycarpum (Hepp) Th. Fr. - Thomson (1997: 546)
- Rhizocarpon riparium Räsänen - Thomson (1997: 548)
- Rhizoplaca chrysoleuca (Sm.) Zopf - Douglas (1974: 587 as Lecanora chrysoleuca), Thomson (1997: 554)
- Rhizoplaca melanophthalma (Ramond) Leuck. & Poelt - Douglas (1974: 587 as Lecanora melanophthalma), Thomson (1997: 555)
- Rhizoplaca peltata (Ramond) Leuck. & Poelt - Thomson (1997: 555)
- Rinodina conradii Körb. - Thomson (1997: 563)
- Rinodina exigua (Ach.) S. Gray - Herre (1917: ), Douglas (1974: 590)
- Rinodina hallii Tuck. - Herre (1917: ), Douglas (1974: 590)
- Rinodina mniaraea (Ach.) Körb. - Douglas (1974: 590), Thomson (1997: 567)
Rinodina novomexicana B. de Lesd. - Eyerdam (1960: 109)
- Rinodina turfacea (Wahlenb.) Körb. - Herre (1917: ), Douglas (1974: 590), Thomson (1997: 571)
- Sagiolechia rhexoblephara (Nyl.) Zahlbr. - Thomson (1997: 575)
- Sarcogyne bicolor H. Magn. - Eyerdam (1960: 109), Douglas (1974: 590)
- Sarcogyne simplex (Dav.) Nyl. - Howard (1950: ), Douglas (1974: 590)
- Scoliciosporum umbrinum (Ach.) Arnold - Thomson (1997: 585)
- Solorina crocea (L.) Ach. - Herre (1917: ), Howard (1950: ), Douglas (1974: 590), Thomson (1984: 387)
- Solorina saccata (L.) Ach. - Herre (1943: ), Douglas (1974: 590)
- Sphaerophorus fragilis (L.) Pers. - Eyerdam (1960: 109), Douglas (1974: 590), Thomson (1984: 392)
- Sphaeophorus globosus (Huds.) Vain. - Herre (1917: ), Howard (1950: ), Douglas (1974: 590)
- Sporastatia testudinea (Ach.) A. Massal. - Howard (1950: ), Douglas (1974: 590), Thomson (1997: 589)
- Staurothele areolata (Ach.) Lettau - Thomson (1997: 592)
- Staurothele clopima (Wahlenb. ex Ach.) Th. Fr. - Howard (1950: ), Douglas (1974: 590)
- Staurothele drummondii (Tuck.) Tuck. - Thomson (1997: 595)
- Staurothele fissa (Tayler) Zwackh. - Thomson (1997: 596)
- Staurothele glacialis Herre - Herre (1943: ), Douglas (1974: 591) Typus ???
- Staurothele perradiata Lynge - Douglas (1974: 591)
- Stereocaulon albicans Th. Gr. - Douglas (1974: 591)
- Stereocaulon alpinum Laur. - Howard (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 400)
- Stereocaulon condensatum Hoffm. - Douglas (1974: 591)
- Stereocaulon depreaultii Del. - Imshaug (1957: ), Douglas (1974: 591)
- Stereocaulon glareosum (Sav.) H. Magn. - Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 412)
- Stereocaulon grande (Magn.) H. Magn. - Thomson (1984: 413)
- Stereocaulon intermedium (Sav.) H. Magn. - Douglas (1974: 591), Thomson (1984: 417)
- Stereocaulon paschale (L.) Hoffm. - Herre (1917: ), Douglas (1974: 591), Thomson (1984: 418)
- Stereocaulon rivulorum H. Magn. - Douglas (1974: 591), Thomson (1984: 421)
- Stereocaulon saxatile H. Magn. - Thomson (1984: 423)
- Stereocaulon subalbicans Lamb. - Imshaug (1957: ), Douglas (1974: 591)
- Stereocaulon tomentosum E. Fries - Howard (1950: ), Douglas (1974: 591), Thomson (1984: 428)
- Stereocaulon vesuvianum Pers. - Howard (1950: ), Douglas (1974: 591)
- Sticta weigelii (Isert ex Ach.) Vain. - Douglas (1974: 591), Thomson (1984: 434)
- Strangospora moriformis (Ach.) Stein - Thomson (1997: 599)
- Tephromela armeniaca (DC. in Lam. & DC.) Hertel & Rambold - Thomson (1997: 60)
- Tephromela atra (Huds.) Hafellner - Thomson (1997: 633)
- Thamnolia subuliformis (Ehrh.) Culb. - Douglas (1974: 591), Thomson (1984: 438)
- Thamnolia vermicularis (Sw.) Ach. - Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 438)
- Thelotrema lepadinum (Ach.) Ach. - Herre (1917: ), Douglas (1974: 591)
- Tholurna dissimilis (Norm.) Norm. - Otto (1972: ), Douglas (1974: 591)
- Toninia aromatica (Turner ex Sm.) A. Massal. - Herre (1943: ), Douglas (1974: 591), Thomson (1997: 613)
- Toninia lobulata (Sommerf.) Lynge - Thomson (1997: 617)
- Toninia ruginosa (Tuck.) Herre - Howard (1950: ), Douglas (1974: 591)
- Toninia squalida (Schleicher ex Ach.) A. Massal. - Howard (1950: ), Douglas (1974: 591), Thomson (1997: 619)
- Trapelia coarctata (Turner ex Sm. & Sow.) M. Choisy - Eyerdam (1960: ), Douglas (1974: 591), Thomson (1997: 621)
- Trapeliopsis granulosa (Hoffm.) Lumbsch - Thomson (1997: 624)
- Umbilicaria angulata Tuck. - Llano (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 442)
- Umbilicaria arctica (Ach.) Nyl. - Thomson (1984: 444)
- Umbilicaria cylindrica (L.) Del. in Duby - Herre (1917: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 448)
- Umbilicaria deusta (L.) Baumg. - Howard (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 449)
- Umbilicaria havaasii Llano - Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 451)
- Umbilicaria hyperborea (Ach.) Hoffm. - Herre (1957: ), Llano (1950: ), Howard (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 453)
- Umbilicaria lambii Imshaug - Imshaug (1957: ) Typus ???
- Umbilicaria phaea Tuck. - Llano (1950: ), Douglas (1974: 591), Thomson (1984: 455)
- Umbilicaria polyphylla (L.) Baumg. - Thomson (1984: 457)
- Umbilicaria polyrrhiza (L.) Fr. - Thomson (1984: 27 as Actinogyra polyrrhiza)
- Umbilicaria proboscidea (L.) Schrad. - Llano (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 458)
- Umbilicaria torrefacta (Lightf.) Schrad. - Herre (1917: ), Llano (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 459)
- Umbilicaria vellea (L.) Ach. - Herre (1943: ), Llano (1950: ), Howard (1950: ), Douglas (1974: 591), Thomson (1984: 460)
Usnea capillaris Mot. - Eyerdam (1960: 109)
- Usnea cavernosa Tuck. - Thomson (1984: 463)
Usnea comosa (Ach.) Röhl - Eyerdam (1960: 109)
Usnea compacta Mot. - Eyerdam (1960: 109)
- Usnea dasypoga (Ach.) Röhl. - Eyerdam (1960: 109 as Usnea dasypoga var. emena), Thomson (1984: 465)
- Usnea florida (L.) Wigg. - Herre (1917: ), Douglas (1974: 591)
Usnea glabrata - Eyerdam (1960: 109)
- Usnea glabrescens (Nyl. ex Vain.) Vain. - Eyerdam (1960: 109), Douglas (1974: 591)
- Usnea hesperina Mot. - Geiser et al. (2004: 108)
- Usnea hirta (L.) F. H. Wigg. - Herre (1917: ), Howard (1955: ), Douglas (1974: 591), Thomson (1984: 467)
- Usnea longissima Ach. - Douglas (1974: 591)
Usnea mollis - Eyerdam (1960: 109)
- Usnea plicata (L.) Wigg. - Herre (1917: ), Douglas (1974: 591) Misidentification according to Hale and Culberson (1970) see Douglas
- Usnea scabrata Nyl. subsp. nylanderiana Motyka - Thomson (1984: 468)
Usnea sorediifera - Eyerdam (1960: 110)
Usnea stuppea - Eyerdam (1960: 110)
- Usnea subfloridana Stirt. - Thomson (1984: 469)
- Usnea substerilis Motyka - Thomson (1984: 470)
- Usnea trichodea Ach. - Eyerdam (1960: 110), Douglas (1974: 591)
- Verrucaria acrotella Ach. - Douglas (1974: 591)
- Verrucaria ceuthocarpa Wahlenb. - Thomson (1997: 635)
- Verrucaria hydrela Ach. - Eyerdam (1960: 110), Douglas (1974: 591)
- Verrucaria margacea (Wahlenb. in Ach.) Wahlenb. - Thomson (1997: 639)
- Verrucaria maura Wahlenb. - Thomson (1997: 640)
- Verrucaria mucosa Wahlenb. - Eyerdam (1960: 110), Thomson (1997: 641)
- Verrucaria nigrescens Pers. - Herre (1917: ), Douglas (1974: 591)
- Verrucaria striatula Wahlenb. - Thomson (1997: 645)
- Vulpicida tilesii (Ach.) J.-E. Mattsson & M. J. Lai - Glew (1994: 83)
- Xanthomendoza fallax (Hepp in Arnold) xxx - Eyerdam (1960: 110 as Xanthoria fallax), Thomson (1984: 486 as Xanthoria fallax)
- Xanthoparmelia conspersa (Ach.) xxx - Howard (1950: ), Douglas (1974: 589 as Parmelia conspersa)
- Xanthoparmelia taractica (Kremp.) Hale - Thomson (1984: 480)
- Xanthoria candelaria (L.) Arnold - Herre (1943: ), Douglas (1974: 591), Thomson (1984: 483)
Xanthoria candelaria var. leprosa Hillm. - Eyerdam (1960: 110)
- Xanthoria elegans (Link.) Th. Fr. - Herre (1917: ), Howard (1950: ), Douglas (1974: 591), Thomson (1984: 484)
- Xanthoria polycarpa (Ehrh.) Rieber - Herre (1917: ), Howard (1950: ), Douglas (1974: 591), Thomson (1984: 487)
- Xanthoria sorediata (Vain.) Poelt - Thomson (1984: 487)
- Xylographa abietina (Pers.) Zahlbr. - Thomson (1997: 646)
- Xylographa vitiligo (Ach.) J. R. Laundon - Thomson (1997: 647)