Checklist of lichens of Washington (USA)
Version 31 December 2017
- Acarospora americana H. Magn. - Eyerdam (1960: 107)
- Acarospora fuscata (Nyl.) Arnold - Douglas (1974: 584), Thomson (1997: 24)
- Acarospora schleicheri (Ach.) A. Massal. - Thomson (1997: 33)
- Acarospora elevata H. Magn. - Douglas (1974: 584 as Acarospora washingtonensis)
- 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.) Stizenb. - Thomson (1984: 38)
- Allantoparmelia alpicola (Th. Fr.) Essl. - Imshaug (1957 as Parmelia alpicola), Douglas (1974: 589 as Parmelia alpicola), Thomson (1984: 299 sub Parmelia alpicola)
- Amandinea punctata (Hoffm.) Coppins & Scheid. - Thomson (1997: 138 sub Buellia punctata)
- Amygdalaria panaeola (Ach.) Hertel & Brodo - Thomson (1997: 42)
- Arthonia radiata (Pers.) Ach. - Douglas (1974: 584)
- Arthothelium norvegicum Coppins & Tønsberg - Tønsberg & Williams (2006: 80 First record for North America)
- Aspicilia aliena (Zahlbr.) Oxner - Thomson (1997: 58)
- Aspicilia cinerea (L.) Körb. - Thomson (1997: 68)
- Aspicilia laevata (Ach.) Arnold - Herre (1943 as Lecanora laevata), Douglas (1974: 587 as Lecanora laevata)
- Aspicilia supertegens Arnold - Douglas (1974: 587 as Lecanora supertegens), Thomson (1997: 95)
- Athallia holocarpa (Hoffm.) Arup, Frödén & Søchting - Douglas (1974: 585 as Caloplaca holocarpa), Thomson (1997: 164 as Caloplaca holocarpa)
- Athallia scopularis (Nyl.) Arup, Frödén & Søchting - Thomson (1997: 168 as Caloplaca scopularis)
- Bacidia rubella (Hoffm.) A. Massal. - Thomson (1997: 107)
- Bactrospora cascadensis Ponzetti & McCune - Ponzetti & McCune (2006: 86 Type)
- Baeomyces rufus (Huds.) Rebent. - Douglas (1974: 584), Thomson (1984: 52)
- Bellemerea alpina (Sommerf.) Clauz. & Roux - Herre (1917: as Lecanora alpina), Douglas (1974: 587 as Lecanora alpina), Thomson (1997: 115)
- Bellemerea cinereorufescens (Ach.) Clauz. & Roux - Thomson (1997: 116)
- Biatora vernalis (L.) Fr. - Thomson (1997: 389 as Lecidea vernalis)
- Biatorella hemisphaerica Anzi - Thomson (1997: 119)
- Bilimbia lobulata (Sommerf.) Lynge - Thomson (1997: 617 as Toninia lobulata)
- Bilimbia sabuletorum (Schreb.) Arnold - Thomson (1997: 422 as Mycobilimbia sabuletorum)
- Blastenia ferruginea (Hudson) Th. Fr. - Douglas (1974: 584 as Caloplaca ferruginea)
- Brodoa oroarctica (Krog) Goward - Douglas (1974: 586 erroneously as Hypogymnia intestiniformis), Thomson (1984: 239 as Hypogymnia oroacrctica)
- Bryobilimbia hypnorum (Lib.) Fryday, Printzen & S. Ekman - Douglas (1974: 588 as Lecidea sanguineoatra), Thomson (1997: 351 as Lecidea hypnorum)
- Bryobilimbia hypnorum (Wulf.) Ach. -
- Bryonora castanea (Hepp) Poelt - Thomson (1997: 122)
- Bryoplaca jungermanniae (Vahl) Søchting, Frödén & Arup - Herre (1917: as Caloplaca jungermanniae), Douglas (1974: 585 as Caloplaca jungermanniae), Thomson (1997: 166 as Caloplaca jungermanniae)
- Bryoplaca tetraspora (Nyl.) Søchting, Frödén & Arup - Thomson (1997: 172 as Caloplaca tetraspora)
- 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 pikei Brodo & D. Hawksw. - Eyerdam (1960: 107 as Alectoria cana)
- Bryoria pseudocapillaris Brodo & D. Hawksw. - Geiser et al. (2004: 105)
- Bryoria pseudofuscenscens (Gyeln.) Brodo & D. Hawksw. - Thomson (1984: 63)
- Buellia disciformis (Fr.) Mudd - Douglas (1974: 584), Thomson (1997: 129)
- Buellia epigaea (Pers.) Tuck. - Douglas (1974: 584)
- Buellia erubescens Arnold - Douglas (1974: 584 as Buellia zahlbruckneri)
- 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 exsecuta (Nyl.) Dalla Torre & Sarnth. - Thomson (1997: 160)
- Caloplaca fraudans (Th. Fr.) Oliv. - Thomson (1997: 162)
- Caloplaca saxicola (Hoffm.) Nordin - Douglas (1974: 585 sub Caloplaca murorum)
- Caloplaca stillicidiorum (Vahl) Lynge - Douglas (1974: 585), Thomson (1997: 172)
- Calvitimela armeniaca (DC. in Lam. & DC.) Hertel & Rambold - Thomson (1997: 60 as Tephromela armeniaca)
- Candelariella aurella (Hoffm.) Zahlbr. - Herre (1917:), Douglas (1974: 585), Thomson (1997: 182)
- Candelariella citrina B. de Lesd. - Douglas (1974: 585 as Candelariella terrigena), Thomson (1997: 187 as Candelariella terrigena)
- Candelariella vitellina (Hoffm.) Müll. Arg. - Thomson (1997: 189)
- Catillaria glauconigrans (Tuck.) Hasse - Thomson (1997: 197)
- Catinaria atropurpurea (Schaer.) Vezda & Poelt - Thomson (1997: 201)
- Cetraria aculeata (Schreb.) Fr. - Imshaug (1957: ), Douglas (1974: 586 as Cornicularia aculeata), Thomson (1984: 198 as Cornicularia aculeata)
- Cetraria ericetorum Opiz subsp. ericetorum - Douglas (1974: 585), Thomson (1984: 79)
- Cetraria islandica (L.) Ach. - Herre (1917:), Howard (1950:), Imshaugh (1957:), Douglas (1974: 585), Thomson (1984: 84)
- Cetraria laevigata Rass. - Thomson (1984: 88)
- Cetrariella commixta(Nyl.) A. Thell & Kärnefelt - Imshaugh (1957: as Cetraria commixta), Douglas (1974: 585 as Cetraria commixta), Thomson (1984: 75 as Cetraria commixta)
- Cetrelia cetrarioides (Del. ex Duby) W. L. Culb. & C. F. Culb. - Eyerdam (1960: 109 as Parmelia cetrarioides), Culberson & Culberson (1968), Douglas (1974: 585), Thell et al. (1998: 309 DNA: ITS)
- Chaenotheca furfuracea (L.) Tibell - Eyerdam (1960: 108 as Coniocybe furfuracea), Thomson (1997: 210 as Coniocybe furfuracea)
- Circinaria caesiocinerea (Nyl. ex Malbr.) A. Nordin, Savić & Tibell - Douglas (1974: 587 as Lecanora caesiocinerea), Thomson (1997: 65 as Aspicilia caesiocinerea)
- Circinaria calcarea (L.) A. Nordin, Savic & Tibell - Herre (1943: as Lecanora calcarea), Howard (1950: as Lecanora calcarea), Douglas (1974: 587 as Lecanora calcarea)
- Circinaria contorta (Hoffm.) A. Nordin, Savic & Tibell - Eyerdam (1960: 108 as Lecanora contorta)
- Circinaria gibbosa H. Magn. - Herre (1917: as Lecanora gibbosula), Howard (1950: as Lecanora gibbosula), Douglas (1974: 587 as Lecanora gibbosula)
- Cladonia arbuscula (Wallr.) Flot. - Herre (1917: ), Douglas (1974: 585 sub Cladina arbuscula), Thomson (1984: 110)
- Cladonia asahinae J. W. Thomson - Thomson (1977: 361 Type in WIS), Ahti (1993: 67)
- Cladonia bellidiflora (Ach.) Schaer. - Herre (1917), Herre (1943: as Cladonia hookeri), Eyerdam (1960), Douglas (1974: 585), Douglas (1974: 586 as Cladonia hookeri), Thomson (1984: 113)
- 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. subsp. cornuta - Eyerdam (1960: 108), Douglas (1974: 586), Thomson (1984: 124)
- Cladonia cryptochlorophaea Asah. - Thomson (1984: 126)
- Cladonia cyanipes (Somm.) Nyl. - Thomson (1984: 127)
- Cladonia deformis (L.) Hoffm. - Douglas (1974: 586)
- Cladonia digitata (L.) Hoffm. - Thomson (1984: 131)
- Cladonia ecmocyna Leight. subsp. ecmocyna - Douglas (1974: 586), Thomson (1984: 132)
- Cladonia fimbriata (L.) Fr. - Douglas (1974: 586), Thomson (1984: 133), Thomson (1984: 144 as Cladonia major)
- Cladonia floerkeana (Fr.) Flörke - Eyerdam (1960: 107), Douglas (1974: 586)
- Cladonia furcata (Huds.) Schrad. - Eyerdam (1960: ), Douglas (1974: 586)
- Cladonia gracilis (L.) Willd. subsp. turbinata (Ach.) Ahti - Thomson (1984: 136)
- Cladonia gracilis (L.) Willd. subsp. gracilis - Herre (1917: ), Eyerdam (1960: ), Douglas (1974: 586), Thomson (1984: 137)
- Cladonia grayi G. Merr. ex Sandst. - Thomson (1984: 139)
- Cladonia macilenta Hoffm. var. macilenta - Herre (1917: ), Eyerdam (1960: 108 as Cladonia macilenta f. granulosa and f. stryracella)
- Cladonia macilenta Hoffm. var. bacillaris (Ach.) Schaer. - Herre (1917: as Cladonia bacillaris), Douglas (1974: 585 as Cladonia bacillaris), Thomson (1984: 111 as Cladonia bacillaris)
- Cladonia macrophyllodes Nyl. - Thomson (1984: 143)
- Cladonia merochlorophaea Asah. - Thomson (1984: 143)
- Cladonia mitis Sandst. - Imshaugh (1957:), Douglas (1974: 585 sub Cladina mitis), Thomson (1984: 148)
- Cladonia multiformis G. Merr. - Douglas (1974: 586), Thomson (1984: 149)
- Cladonia ochrochlora Flörke - Eyerdam (1960: 108)
- Cladonia peziziformis (With.) J. R. Laundon - Eyerdam (1960 as Cladonia capitata), Douglas (1974: 585 as Cladonia capitata)
- Cladonia phyllophora Ehrh. ex Hoffm. - Eyerdam (1960: 108 as Cladonia degenerans f. phyllophora), Douglas (1974: 586), Thomson (1984: 153)
- Cladonia pyxidata (L.) Hoffm. - Herre (1917: ), Imshaug (1957: ), Eyerdam (1960: 108 as Cladonia pyxidata var. neglecta), Douglas (1974: 586), Thomson (1984: 158)
- Cladonia ramulosa (Ach.) Ahti & P. James - Eyerdam (1960: 108 as Cladonia pityrea f. cornuta, f. squamulifera and f. zwackhii), Douglas (1974: 586 as Cladonia pityrea), Thomson (1984: 109 as Cladonia anomaea)
- Cladonia rangiferina (L.) F. H. Wigg. - Herre (1917:), Douglas (1974: 585 sub Cladina rangiferina), Thomson (1984: 159)
- Cladonia squamosa (Scop.) Hoffm. var. squamosa - Herre (1917: ), Douglas (1974: 586), Thomson (1984: 161)
- Cladonia squamosa (Scop.) Hoffm. var. subsquamosa (Nyl. ex Leight.) Vain. - Howard (1950: as Cladonia subsquamosa), Douglas (1974: 586 as Cladonia subsquamosa)
- Cladonia stricta (Nyl.) Nyl. - Thomson (1984: 164)
- Cladonia subulata (L.) F. H. Wigg. - Eyerdam (1960: ), Eyerdam (1960: 108 as Cladonia cornutoradiata), Douglas (1974: 586), Thomson (1984: 168)
- Cladonia sulphurina (Michx.) Fr. - Douglas (1974: 586 as Cladonia gonecha)
- Cladonia trassii Ahti - Eyerdam (1960: 108 as Cladonia lepidota var. stricta f. pterophora), Douglas (1974: 586 as Cladonia lepidota)
- Cladonia turgida Ehrh. ex Hoffm. - Eyerdam (1960: 108), Thomson (1984: 172)
- Cladonia uncialis (L.) Weber ex F. H. Wigg. - Thomson (1984: 173)
- Cladonia verticillata (Hoffm.) Schaer. - Herre (1917: ), Douglas (1974: 586), Thomson (1984: 174)
- Collemopsidium sublitorale (Leight.) Grube & B. D. Ryan - Thomson (1997: 49 as Arthopyrenia sublitoralis)
- Cornicularia normoerica (Gunn.) Du Rietz - Imshaug (1957: ), Douglas (1974: 586), Thomson (1984: 201)
- Cyphelium inquinans (Sm. in Sm. & Sow.) Trevisan - Herre (1917: ), Douglas (1974: 586), Thomson (1997: 212)
- Cyphelium tigillare (Ach.) Ach. - Thomson (1997: 214)
- Dactylina arctica (Hook. f.) Nyl. - Imshaug (1957), Douglas (1974: 586), Thomson (1984: 203)
- Dermatocarpon luridum (Dill. ex With.) J. R. Laundon - Douglas (1974: 586 as Dermatocarpon fluviatile), Thomson (1984: 213 as Dermatocarpon fluviatile)
- Dermatocarpon intestiniforme (Körb.) Hasse - Thomson (1984: 216)
- Dermatocarpon meiophyllizum Vain. - Glavich & Geiser (2004: 139)
- Dermatocarpon miniatum (L.) W. Mann - Howard (1950), Douglas (1974: 586), Thomson (1984: 219)
- Dimelaena oreina (Ach.) Norman - Eyerdam (1960: 109 as Rinodina novomexicana)
- Diploschistes actinostomus (Ach.) Zahlbr. - Herre (1943), Douglas (1974: 586)
- Diploschistes muscorum (Scop.) R. Sant. subsp. muscorum - Thomson (1997: 218)
- Diploschistes scruposus (Schreb.) Norman - Douglas (1974: 586), Thomson (1997: 218)
- Diplotomma alboatrum (Hoffm.) Flot. - Douglas (1974: 584 as Buellia alboatra), Thomson (1997: 127 as Buellia alboatra)
- Erioderma sorediatum D. J. Galloway & P. M. Jørg. - Geiser et al. (2004: 106)
- Esslingeriana idahoensis (Essl.) Hale & M. J. Lai - Esslinger (1971: 366 as Cetraria idahoensis Type in DUKE), Douglas (1974: 585 as Cetraria idahoensis)
- 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)
- Flavocetraria cucullata (Bellardi) Kärnefelt & A. Thell - Imshaugh (1957 as Cetraria cucullata), Douglas (1974: 585 as Cetraria cucullata), Thomson (1984: 76 as Cetraria cucullata)
- Flavocetraria nivalis (L.) Kärnefelt & A. Thell - Imshaugh (1957: as Cetraria nivalis), Douglas (1974: 585 as Cetraria nivalis), Thomson (1984: 92 as Cetraria nivalis)
- Flavoplaca citrina (Hoffm.) Arup, Frödén & Søchting - Thomson (1997: 155 as Caloplaca citrina)
- Frutidella caesioatra (Schaer.) Kalb - Herre (1917: as Lecidea caesioatra), Howard (1950: as Lecidea caesioatra)
- Fuscopannaria cheiroloba (Müll. Arg.) P. M. Jørg. - Jørgensen et al. (2010: 2)
- Fuscopannaria cyanolepra (Tuck.) Herre - Herre (1917: as Parmeliella cyanolepra), Douglas (1974: 589 as Parmeliella cyanolepra)
- Fuscopannaria praetermissa (Nyl.) P. James - Howard (1950: as Parmeliella praetermissa), Douglas (1974: 589 as Parmeliella praetermissa)
- Graphis scripta (L.) Ach. - Howard (1950), Douglas (1974: 586)
- Gyalecta jenensis (Batsch) Zahlbr. - Thomson (1997: 241)
- Heppia lutosa (Ach.) Nyl. - Herre (1917: ), Douglas (1974: 586)
- Heterodermia leucomelos (L.) Poelt - Geiser et al. (2004: 106)
- Hydropunctaria maura (Wahlenb.) Keller, Gueidan & Thüs - Thomson (1997: 640 as Verrucaria maura)
- Hypocenomyce scalaris (Ach. ex Lilj.) M. Choisy - Thomson (1997: 248)
- Hypogymnia amplexa Goward, Björk & Wheeler - Lumbsch et al. (2011: 64 Type in Vancouver, British Columbia, Canada UBC)
- Hypogymnia austerodes (Nyl.) Räsänen - Thomson (1984: 237)
- Hypogymnia enteromorpha (Ach.) Nyl. - Herre (1917: ), Douglas (1974: 586)
- Hypogymnia physodes (L.) Nyl. - Herre (1917: ), Douglas (1974: 587), Thomson (1984: 241)
- Hypogymnia vittata (Ach.) Parrique - Howard (1950), Douglas (1974: 587), Thomson (1984: 243)
- Icmadophila ericetorum (L.) Zahlbr. - Herre (1917: ), Howard (1950: ), Douglas (1974: 587), Thomson (1997: 249)
- Ionaspis lacustris (With.) Lutzoni - Thomson (1997: 245 as Hymenelia lacustris)
- Japewia tornoensis (Nyl.) Tønsberg - Douglas (1974: 588 as Lecidea tornoensis), Thomson (1997: 387 as Lecidea tornoensis)
- Kaernefeltia californica (Tuck.) A. Thell & Goward - Eyerdam (1960: 109 as Nephromopsis californica)
- Lecania dubitans (Nyl.) A. L. Sm. - Herre (1917: as Lecania dimera), Douglas (1974: 587 as Lecania dimera)
- Lecania franciscana (Tuck.) K. Knudsen & Lendemer - Eyerdam (1960: 107 as Catillaria franciscana)
- Lecanora allophana Nyl. - Herre (1917: as Lecanora subfusca), Douglas (1974: 587 as Lecanora subfusca)
- Lecanora cenisia Ach. - Douglas (1974: 587), Thomson (1997: 272)
- Lecanora chlarotera Nyl. - Thomson (1997: 273)
- Lecanora cinereofusca H. Magn. var. cinereofusca - Douglas (1974: 587)
- Lecanora circumborealis Brodo & Vitik. - Herre (1917: as Lecanora coilocarpa), Douglas (1974: 587 as Lecanora coilocarpa), Thomson (1997: 274)
- 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 fuscescens Somm. - Douglas (1974: 588 as Lecidea fuscescens)
- Lecanora hagenii (Ach.) Ach. - Herre (1917: ), Howard (1950: ), Douglas (1974: 587), Thomson (1997:286)
- Lecanora marginata (Schaer.) Hertel & Rambold- Herre (1943: as Lecidea marginata), Douglas (1974: 588 as Lecidea marginata), Thomson (1997: 291)
- Lecanora melaena (Hedl.) Fink - Eyerdam (1960: 108)
- Lecanora muralis (Schreb.) Rabenh. - Howard (1950: ), Eyerdam (1960: 108 as Lecanora diffracta), 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 (Pers.) Ach. - Thomson (1997: 301)
- Lecanora rupicola (L.) Zahlbr. - Douglas (1974: 587), Thomson (1997: 303)
- Lecanora strobilina (Sprengel) Kieffer - Eyerdam (1960: 108 as Lecanora conizaea)
- Lecanora subrugosa Nyl. - Thomson (1997: 308)
- 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)
- Lecanora xylophila Hue - Thomson (1997: 284 as Lecanora grantii)
- Lecidea atrobrunnea (Ramond ex Lam. & DC.) Schaer. subsp. atrobrunnea - Douglas (1974: 587), Thomson (1997: 327)
- Lecidea auriculata Th. Fr. subsp. auriculata - Howard (1950: ), Douglas (1974: 587), Thomson (1997: 329)
- Lecidea cascadensis H. Magn. - Eyerdam (1960: 108)
- Lecidea cinerata Zahlbr. - Douglas (1974: 587)
- Lecidea confluens (W. A. Weber) Ach. - Douglas (1974: 587), Thomson (1997: 339)
- Lecidea furvonigrans (Tuck.) Zahlbr. - Douglas (1974: 588)
- Lecidea fuscoatra (L.) Ach. - Thomson (1997: 347)
- Lecidea lapicida (Ach.) Ach. - Howard (1950: ), Douglas (1974: 588), Thomson (1997: 357), Thomson (1997: 355 as Lecidea lactea)
- Lecidea leucothallina Arnold - Thomson (1997: 360)
- Lecidea lithophila (Ach.) Ach. - Thomson (1997: 362)
- Lecidea paddensis (Tuck.) Zahlbr. - Douglas (1974: 588)
- Lecidea paupercula Th. Fr. - Thomson (1997: 369)
- Lecidea plana Lahm ex Körb. - Douglas (1974: 588)
- Lecidea tessellata Flörke - Herre (1917: ), Howard (1950: ), Douglas (1974: 588), Thomson (1997: 384)
- Lecidella carpathica Körb. - Thomson (1997: 395)
- Lecidella elaeochroma (Ach.) M. Choisy - Herre (1943: ), Douglas (1974: 588), Thomson (1997: 396)
- Lecidella euphorea (Flörke) Hertel - Douglas (1974: 588 as Lecidea glomerulosa), Thomson (1997: 398)
- Lecidella stigmatea (Ach.) Hertel & Leuck. - Douglas (1974: 588), Thomson (1997: 402)
- Lecidella wulfenii (Hepp) Körb. - Thomson (1997: 403)
- Lecidoma demissum (Rutstr.) Gotth. 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 albicans Th. Fr. - Douglas (1974: 591 as Stereocaulon albicans)
- Lepraria membranacea (Dicks.) Vain. - Douglas (1974: 588)
- Lepraria neglecta (Nyl.) Erichsen - Douglas (1974: 588)
- Lepraria subalbicans (I. M. Lamb) Lendemer & Hodkinson - Imshaug (1957: as Stereocaulon subalbicans), Douglas (1974: 591 as Stereocaulon subalbicans), Thomson (1984: 250 as Leprocaulon subalbicans)
- Leptochidium albociliatum (Desm.) M. Choisy - Thomson (1984: 252)
- Leptogium brebissonii Mont. - Geiser et al. (2004: 107)
- Leptogium saturninum (Dicks.) Nyl. Thomson (1984: 262)
- Letharia vulpina (L.) Hue - Herre (1917: ), Douglas (1974: 588)
- Lobaria anomala (Brodo & Ahti) T. Sprib. & McCune - Merrill (Lich. Exs.: 25), Ahti et al. (1987: 95 Type in CANL), McCune et al. (2014: xx)
- 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)
- Megaspora verrucosa (Ach.) Hafellner & V. Wirth - Thomson (1997: 443 as Pachyospora verrucosa)
- Melanelia hepatizon (Ach.) A. Thell - Imshaugh (1957: as Cetraria hepatizon), Douglas (1974: 585 as Cetraria hepatizon), Thomson (1984: 82 as Cetraria hepatizon)
- Melanelixia fuliginosa (Fr. ex Duby) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Eyerdam (1960: 109 as Parmelia fuliginosa)
- Melanelixia glabratula (Lamy) Sandler & Arup - Thomson (1984: 303 sub Parmelia glabratula)
- Melanelixia subaurifera (Nyl.) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Thomson (1984: 316 sub Parmelia subaurifera)
- Melanohalea elegantula (Zahlbr.) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Thomson (1984: 300 sub Parmelia elegantula)
- Melanohalea exasperata (De Not.) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Eyerdam (1960: 109 as Parmelia exasperata)
- Melanohalea exasperatula (Nyl.) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Thomson (1984: 300 sub Parmelia exasperatula)
- Melanohalea infumata (Nyl.) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Imshaug (1957: as Parmelia infumata), Douglas (1974: 589 as Parmelia infumata), Thomson (1984: 304 as Parmelia infumata)
- Melanohalea laciniatula (Flagey ex H. Olivier) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Eyerdam (1960: 109 as Parmelia laciniatula)
- Melanohalea multispora (A. Schneid.) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch - Howard (1950: as Parmelia multispora), Douglas (1974: 589 as Parmelia multispora)
- 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 Type in Bergen, Norway BG)
- Montanelia disjuncta (Erichsen) Divakar, A. Crespo, Wedin & Essl. - Eyerdam (1960: 109 as Parmelia disjuncta), Thomson (1984: 299 sub Parmelia disjuncta)
- Montanelia panniformis (Nyl.) Divakar, A. Crespo, Wedin & Essl. - Howard (1950: as Parmelia panniformis), Douglas (1974: 589 as Parmelia panniformis), Thomson (1984: 309 as Parmelia panniformis)
- Montanelia sorediata (Ach.) Divakar, A. Crespo, Wedin & Essl. - Thomson (1984: 312 sub Parmelia sorediosa)
- Montanelia tominii (Oxner) Divakar, A. Crespo, Wedin & Essl. - Thomson (1984: 317 sub Parmelia substygia)
- Mycobilimbia berengeriana (A. Massal.) Hafellner & V. Wirth - Douglas (1974: 587 as Lecidea berengeriana), Thomson (1997: 331 as Lecidea berengeriana)
- Mycoblastus affinis (Schaer.) Schauer- Thomson (1997: 424)
- Mycoblastus sanguinarius (L.) Norman - Douglas (1974: 588), Thomson (1997: 426)
- Myriospora smaragdula (Wahlenb. ex Ach.) K. Knudsen & B. Abbott - Thomson (1997: 34 as Acarospora smaragdula)
- Nephroma bellum (Spreng.) Tuck. - Wetmore (1960: ), Douglas (1974: 588), Thomson (1984: 278)
- Nephroma helveticum Ach. subsp. helveticum - 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)
- Niebla cephalota (Tuck.) Rundel & Bowler - Geiser et al. (2004: 107)
- Nodobryoria abbreviata (Müll. Arg.) Common & Brodo - Cole & Hawksworth (2004: 1)
- Nodobryoria oregana (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 tartarea (L.) A. Massal. - Herre (1917: ), Howard (1970: ), Douglas (1974: 589)
- Ochrolechia upsaliensis (L.) A. Massal. - Douglas (1974: 589), Thomson (1997: 436)
- Opegrapha pulicaris (Hoffm.) Schrad. - Herre (1917: ), Douglas (1974: 589)
- Ophioparma lapponica (Räsänen) Hafellner & Rogers - Douglas (1974: 586 as Haematomma lapponicum), Thomson (1997: 440)
- Orphniospora moriopsis (A. Massal.) D. Hawksw. - Thomson (1997: 441)
- Pannaria rubiginosa (Thunb.) Delise - Howard (1950: ), Douglas (1974: 589), Geiser et al. (2004: 107)
- Parmelia barrenoae Divakar, M. C. Molina & A. Crespo - Hodkinson et al. (2010: 3)
- Parmelia omphalodes (L.) Ach. - Thomson (1984: 308)
- Parmelia saxatilis (L.) Ach. - Howard (1950: ), Imshaug (1957), Douglas (1974: 589), Thomson (1984: 310)
- Parmelia sulcata Tayl. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 318)
- Parmeliella tryptophylla (Ach.) Müll. - Thomson (1984: 321)
- Parmeliopsis ambigua (Wulf.) Nyl. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 325)
- Parmeliopsis hyperopta (Ach.) Arnold - Herre (1943: ), Douglas (1974: 589), Thomson (1984: 326)
- Parmotrema perlatum (Huds.) M. Choisy - Herre (1917 as Parmelia perlata), Douglas (1974: 589 as Parmelia perlata)
- Peltigera aphthosa (L.) Willd. - Herre (1917: ), Thomson (1950: ), Howard (1950: ), Eyerdam (1960: ), Douglas (1974: 589), Thomson (1984: 329)
- Peltigera canina (L.) Willd. - Herre (1917: ), Howard (1950: ), Douglas (1974: 589)
- Peltigera collina (Ach.) Schrad. - Thomson (1950: ), Douglas (1974: 589), Thomson (1984: 334)
- Peltigera didactyla (With.) J. R. Laundon - Herre (1917: as Peltigera spuria), Thomson (1950: as Peltigera spuria), Douglas (1974: 589 as Peltigera spuria), Thomson (1984: 332 as Peltigera canina f. sorediata)
- Peltigera horizontalis (Huds.) Baumg. - Thomson (1984: 337)
- Peltigera lepidophora (Nyl. ex Vain.) Bitter - Imshaug (1950: ), Douglas (1974: 589), Thomson (1984: 338)
- Peltigera leucophlebia (Nyl.) Gyelnik - Eyerdam (1960: 109 as Peltigera aphthosa var. variolosa), Thomson (1984: 330 as Peltigera aphthosa var. leucophlebia)
- 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 polydactylon (Neck.) Hoffm. - Herre (1917: ), Thomson (1950: ), Imshaug (1957: ), Douglas (1974: 589), Thomson (1984: 343)
- Peltigera rufescens (Weiss) Humb. - Thomson (1984: 333 as Peltigera canina var. rufescens)
- Peltigera scabrosa Th. Fr. - Thomson (1984: 344)
- Peltigera venosa (L.) Hoffm. - Herre (1917: ), Howard (1950), Douglas (1974: 589), Thomson (1984: 345)
- Pertusaria carneopallida (Nyl.) Anzi ex Nyl. - Thomson (1997: 451)
- Pertusaria glaucomela (Tuck.) Nyl. - Douglas (1974: 589)
- Pertusaria leioplaca DC. - Herre (1917: ), Douglas (1974: 589)
- Pertusaria sommerfeltii (Flörke ex Sommerf.) Fr. - Thomson (1997: 461)
- Phaeophyscia endococcina (Körb.) Moberg - Thomson (1984: 348)
- Phaeophyscia sciastra (Ach.) Moberg - Thomson (1984: 349)
- Physcia adscendens (Fr.) Oliv. - Thomson (1984: 352)
- Physcia aipolia (Humb.) Fürnr. var. aipolia - Herre (1917: ), Thomson (1963), Douglas (1974: 589), Thomson (1984: 353)
- Physcia caesia (Hoffm.) Hampe ex Fürnr. - Howard (1950: ), Douglas (1974: 589), Thomson (1984: 354)
- Physcia dubia (Hoffm.) Lettau - Imshaug (1957: ), Imshaug (1957: as Physcia teretiuscula), Thomson (1963: ), Thomson (1963: as Physcia teretiuscula), Douglas (1974: 590), Douglas (1974: 590 as Physcia teretiuscula), Thomson (1984: 355)
- Physcia magnussonii Frey - Esslinger (1979: 212 First record for North America)
- Physcia phaea (Tuck.) Thoms. - Thomson (1963: as Physcia cascadensis), Douglas (1974: 590 as Physcia cascadensis), Thomson (1984: 356)
- Physcia stellaris (L.) Nyl. - Howard (1950: ), Douglas (1974: 590)
- Physcia tenella (Scop.) DC. - Eyerdam (1960: 109)
- Physcia tribacia (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)
- Pilophoron acicularis (Ach.) Th. Fr. - Eyerdam (1960: 109), Douglas (1974: 590)
- Pilophoron cereolus (Ach.) Th. Fr. in Hellbom - Herre (1917: ), Howard (1950: ), Howard (1955: ), Douglas (1974: 590)
- Pilophoron clavatus Th. Fr. - Herre (1917: ), Douglas (1974: 590)
- Placopsis gelida (L.) Lindsay - Thomson (1997: 472)
- Placynthiella uliginosa (Schrad.) Coppins & P. James - Thomson (1997: 475)
- Platismatia glauca (L.) W. L. Culb. & C. F. Culb. - Herre (1917: ), Howard (1950: ), Howard (1955), Douglas (1974: 590), Thomson (1984: 368)
- Platismatia herrei (Imshaug) W. L. Culb. & C. F. Culb. - Herre (1917: ), Howard (1950: ), Culberson & Culberson (1968: ), Douglas (1974: 590)
- Platismatia lacunosa (Ach.) W. L. Culb. & C. F. Culb. - Herre (1917: ), Douglas (1974: 590)
- Platismatia norvegica (Lynge) W. L. Culb. & C. F. Culb. - Douglas (1974: 590), Thell et al. (1998: 309 DNA: ITS)
- Platismatia stenophylla (Tuck.) W. L. Culb. & C. F. Culb. - Thell et al. (1998: 309 DNA: ITS)
- Placopsis gelida (L.) Linds. - Herre (1917: ), Douglas (1974: 590)
- Placynthiella uliginosa (Schrad.) Coppins & P. James - Douglas (1974: 588 as Lecidea uliginosa)
- Pleopsidium chlorophanum (Wahlenb. ex Ach.) Zopf - Magnusson (1956: 15 as Acarospora weldensis), Douglas (1974: 584 sub Acarospora chlorophana)
- Pleopsidium flavum (Bellardi) Körb. - Thomson (1997: 29 as Acarospora oxytona), Knudsen (2011: 83 as Pleopsidium stenosporum)
- Polycauliona candelaria (L.) Frödén, Arup, & Søchting - Herre (1943: as Xanthoria candelaria), Douglas (1974: 591 as Xanthoria candelaria), Thomson (1984: 483 as Xanthoria candelaria)
- Polycauliona polycarpa (Hoffm.) Frödén, Arup, & Søchting - Herre (1917: as Xanthoria polycarpa), Howard (1950: as Xanthoria polycarpa), Douglas (1974: 591 as Xanthoria polycarpa), Thomson (1984: 487 as Xanthoria polycarpa)
- Polychidium muscicola (Sw.) Gray - Thomson (1984: 370)
- Polysporina simplex (Taylor) Vezda - Howard (1950: as Sarcogyne simplex), Douglas (1974: 590 as Sarcogyne simplex), Thomson (1997: 486)
- Polysporina subfuscescens (Nyl.) K. Knudsen & Kocourk. - Eyerdam (1960: 109 as Sarcogyne bicolor), Douglas (1974: 590 as Sarcogyne bicolor)
- Porina radicicola P. M. McCarthy & Tønsberg - McCarthy & Tønsberg (1998: 245 Type in Bergen, Norway BG)
- Porpidia albocaerulescens (Wulf.) Hertel & Knoph - Howard (1950: as Lecidea albocaerulescens), Douglas (1974: 587 as Lecidea albocaerulescens)
- Porpidia crustulata (Ach.) Hertel & Knoph - Douglas (1974: 587 as Lecidea crustulata)
- Porpidia glaucophaea (Körb.) Hertel & Knoph - Douglas (1974: 588 as Lecidea glaucophaea)
- Porpidia grisea Gowan - Thomson (1997: 493)
- Porpidia macrocarpa (DC.) Steud. - Eyerdam (1960: as Lecidea macrocarpa), Eyerdam (1960: 109 as Lecidea platycarpa), 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)
- Protopannaria pezizoides (Web.) Trev. - Thomson (1984: 294 as Pannaria pezizoides)
- Protoparmelia badia (Hoffm.) Hafellner - Thomson (1997: 269 as Lecanora badia)
- 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)
- Psora globifera (Ach.) A. Massal. - Howard (1950: as Lecidea globifera), Douglas (1974: 588 as Lecidea globifera), Thomson (1997: 508)
- Psora nipponica (Zahlbr.) Gotth. Schneider - Thomson (1997: 510)
- Psora rubiformis (Ach.) Hook. - Herre (1917: as Lecidea rubiformis), Douglas (1974: 588 as Lecidea rubiformis)
- Psoroma hypnorum (Vahl) Gray - Douglas (1974: 590), Thomson (1984: 375)
- Psorula rufonigra (Tuck.) Nyl. - Douglas (1974: 588 as Lecidea rufonigra)
- 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. subsp. inflata - Herre (1917:), Douglas (1974: 590)
- Ramalina pollinaria (Westr.) Ach. - Geiser et al. (2004: 109)
- Ramalina roesleri (Hoechst. ex Schaer.) (Hochst. ex Schaerer) Hue - Thomson (1984: 233 as Fisturiella roesleri)
- Ramboldia cinnabarina (Sommerf.) Kalb, Lumbsch & Elix - Thomson (1997: 336 as Lecidea cinnabarina)
- Ramboldia gowardiana (T. Sprib. & Hauck) Kalb, Lumbsch & Elix - Spribille & Hauck (2003: 560 as Pyrrhospora gowardiana)
- 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) Beltr. - 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 Flot.) Arnold - Thomson (1997: 539)
- Rhizocarpon hochstetteri (Körb.) Vain. - Herre (1943: ), Douglas (1974: 590), Thomson (1997: 540)
- Rhizocarpon jemtlandicum (Malme) 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 (Ram.) Leuck. & Poelt - Douglas (1974: 587 as Lecanora melanophthalma), Thomson (1997: 555)
- Rhizoplaca peltata (Ram.) Leuck. & Poelt - Thomson (1997: 555)
- Rinodina aurantiaca Sheard - Sheard & Mayrhofer (2002: 653)
- 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 marysvillensis H. Magn. - Magnusson (1932: 31 Type in Uppsala, Sweden UPS), Sheard (2010: 132)
- Rinodina mniaraea (Ach.) Körb. - Douglas (1974: 590), Thomson (1997: 567)
- Rinodina stictica Sheard & Tønsberg - Sheard & Tønsberg (1995: 41 Type in BG), Sheard (2010: 188)
- Rinodina turfacea (Wahlenb.) Körb. - Herre (1917: ), Douglas (1974: 590), Thomson (1997: 571)
- Romjularia lurida (Ach.) Timdal - Howard (1950: as Lecidea lurida), Douglas (1974: 588 as Lecidea lurida), Thomson (1997: 509 as Psora lurida)
- Rusavskia elegans (Link) S. Y. Kondr. & Kärnefelt - Herre (1917: as Xanthoria elegans), Howard (1950: as Xanthoria elegans), Douglas (1974: 591 as Xanthoria elegans), Thomson (1984: 484 as Xanthoria elegans)
- Rusavskia sorediata (Vain.) S. Y. Kondr. & Kärnefelt - Thomson (1984: 487 as Xanthoria sorediata)
- Sagiolechia rhexoblephara (Nyl.) Zahlbr. - Thomson (1997: 575)
- Sarcogyne mitziae K. Knudsen, Kocourk. & McCune - Knudsen et al. (2013: 122)
- Scoliciosporum umbrinum (Ach.) Arnold - Thomson (1997: 585)
- Scytinium lichenoides (L.) Otálora, P. M. Jørg. & Wedin - Howard (1950: as Leptogium lichenoides), Douglas (1974: 588 as Leptogium lichenoides), Thomson (1984: 257 as Leptogium lichenoides)
- Scytinium palmatum (Hudson) Otálora, P. M. Jørg. & Wedin - Thomson (1984: 260 as Leptogium palmatum)
- Scytinium rivale (Tuck.) Otálora, P. M. Jørg. & Wedin - Glavich & Geiser (2007: 8 as Leptogium rivale)
- Scytinium gelatinosum (Huds.) Mass. - Thomson (1984: 263 as Leptogium sinuatum)
- Scytinium subaridum P. M. Jørg. & Goward - Aragón et al. (2004: 165 as Leptogium subaridum)
- Scytinium subtile (Schrad.) Otálora, P. M. Jørg. & Wedin - Thomson (1984: 259 as Leptogium minutissimum)
- Scytinium tenuissimum (Dicks.) Fr. - Herre (1917: as Leptogium tenuissimum), Douglas (1974: 588 as Leptogium tenuissimum)
- 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: 584 as Biatorella kulshanensis), Douglas (1974: 590), Thomson (1997: 589)
- Staurothele areolata (Ach.) Lettau - Thomson (1997: 592)
- Staurothele drummondii (Tuck.) Tuck. - Howard (1950: as Staurothele clopima), Douglas (1974: 590 as Staurothele clopima), Douglas (1974: 591 as Staurothele perradiata), Thomson (1997: 595)
- Staurothele fissa (Tayler) Zwackh - Herre (1943: as Staurothele glacialis Typus?), Douglas (1974: 591 as Staurothele glacialis), Thomson (1997: 596)
- Stereocaulon alpinum Laurer ex Funck - Howard (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 400)
- Stereocaulon condensatum Hoffm. - Douglas (1974: 591)
- Stereocaulon depreaultii Delise ex Nyl. - Imshaug (1957: ), Douglas (1974: 591)
- Stereocaulon glareosum (Savicz) H. Magn. - Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 412)
- Stereocaulon grande (H. Magn.) H. Magn. - Thomson (1984: 413)
- Stereocaulon intermedium (Savicz) H. Magn. - Douglas (1974: 591), Thomson (1984: 417)
- Stereocaulon nivale (Follmann) Fryday - Follmann (xx: xx Type in ), Follmann & Huneck (1977: 176)
- 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 tomentosum E. Fries - Howard (1950: ), Douglas (1974: 591), Thomson (1984: 428)
- Stereocaulon vesuvianum Pers. - Howard (1950: ), Douglas (1974: 591)
- Strangospora moriformis (Ach.) Stein - Thomson (1997: 599)
- Tephromela atra (Huds.) Hafellner - Thomson (1997: 633)
- Tetramelas geophila (Flörke ex Sommerf.) Norman - Thomson (1997: 133 as Buellia geophila)
- Tetramelas papillatus (Sommerf.) Kalb - Douglas (1974: 584 as Buellia papillata), Thomson (1997: 136 as Buellia papillata)
- Thamnolia subuliformis (Ehrh.) W. L. Culb. - Douglas (1974: 591), Thomson (1984: 438)
- Thamnolia vermicularis (Sw.) Ach. ex Schaer. - Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 438)
- Thelomma ocellatum (Körb.) Tibell - Thomson (1997: 213 as Cyphelium ocellatum)
- 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 ruginosa (Tuck.) Herre subsp. ruginosa - 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 - Howard (1950: as Lecidea granulosa), Thomson (1997: 624)
- Tuckermannopsis chlorophylla (Willd.) Vain. - Herre (1917: as Cetraria chlorophylla), Douglas (1974: 585 as Cetraria chlorophylla), Thomson (1984: 73 as Cetraria chlorophylla)
- Tuckermannopsis ciliaris (Ach.) Gyeln. - Douglas (1974: 585 as Cetraria ciliaris)
- Tuckermannopsis platyphylla (Tuck.) Hale - Herre (1917 as Cetraria platyphylla), Douglas (1974: 585 as Cetraria platyphylla)
- Tuckermannopsis subalpina (Imshaug) Kärnefelt - Douglas (1974: 585 as Cetraria subalpina)
- 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 decussata (Vill.) Zahlbr. - Imshaug (1950: as Omphalodiscus decussatus), Douglas (1974: 589 as Omphalodiscus decussatus), Thomson (1984: 288 as Omphalodiscus decussatus)
- 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. var. hyperborea - Herre (1957: ), Llano (1950: ), Howard (1950: ), Imshaug (1957: ), Douglas (1974: 591), Thomson (1984: 453)
- Umbilicaria lambii Imshaug - Imshaug (1957: ) Typus ???
- Umbilicaria lyngei Schol. - Douglas (1974: 584 as Agyrophora lyngei), Thomson (1984: 30 as Agyrophora lyngei)
- Umbilicaria phaea Tuck. - Llano (1950: ), Douglas (1974: 591), Thomson (1984: 455)
- Umbilicaria polaris (Schol.) Zahlbr. - Thomson (1984: 289 erroneously as Omphalodiscus krascheninnikovii)
- 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 rigida (Du Rietz) Frey - Thomson (1984: 31 as Agyrophora rigida)
- Umbilicaria scholanderi (Llano) Krog - Thomson (1984: 32 as Agyrophora scholanderi)
- 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)
- Umbilicaria virginis Schaerer - Imshaug (1957: as Omphalodiscus virginis), Douglas (1974: 589 as Omphalodiscus virginis), Thomson (1984: 290 as Omphalodiscus virginis)
- Usnea capillaris Mot. - Eyerdam (1960: 109)
- Usnea cavernosa Tuck. - Thomson (1984: 463)
- Usnea dasypoga (Ach.) Röhl. - Eyerdam (1960: 109 as Usnea dasypoga var. emena), Thomson (1984: 465)
- Usnea florida (L.) Weber ex F. H. Wigg. - Herre (1917: ), Douglas (1974: 591)
- Usnea glabrata (Ach.) Vain - Eyerdam (1960: 109)
- Usnea glabrescens (Nyl. ex Vain.) Vain. - Eyerdam (1960: 109), Eyerdam (1960: 109 as Usnea compacta), Douglas (1974: 591)
- Usnea hirta (L.) Weber ex F. H. Wigg. - Herre (1917: ), Howard (1955: ), Douglas (1974: 591), Thomson (1984: 467)
- Usnea longissima Ach. - Douglas (1974: 591)
- Usnea fragilescens var. mollis - Eyerdam (1960: 109 as Usnea mollis)
- Usnea scabrata Nyl. - Thomson (1984: 468 as Usnea scabrata subsp. nylanderiana)
- Usnea sphacelata R. Br. - Weber (1973: as Neuropogon lambii), Douglas (1974: 588 as Neuropogon lambii)
- Usnea subfloridana Stirt. - Eyerdam (1960: 109 as Usnea comosa), Thomson (1984: 469)
- Usnea subgracilis Vain. - Geiser et al. (2004: 108 as Usnea hesperina)
- Usnea substerilis Motyka - Eyerdam (1960: 110 as Usnea sorediifera), Eyerdam (1960: 110 as Usnea stuppea), Thomson (1984: 470)
- Usnea trichodea Ach. - Eyerdam (1960: 110), Douglas (1974: 591)
- Variolaria amara Ach. - Herre (1917: as Pertusaria amara), Douglas (1974: 589 as Pertusaria amara)
- 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 nigrescens Pers. - Herre (1917: ), Douglas (1974: 591)
- Vulpicida pinastri (Scop.) J.-E. Mattsson & M. J. Lai - Imshaugh (1957: as Cetraria pinastri), Thomson (1984: 93 as Cetraria pinastri)
- Vulpicida tilesii (Ach.) J.-E. Mattsson & M. J. Lai - Glew (1994: 83)
- Wahlenbergiella mucosa (Wahlenb.) Gueidan & Thüs - Eyerdam (1960: 110 as Verrucaria mucosa), Thomson (1997: 641 as Verrucaria mucosa)
- Wahlenbergiella striatula (Wahlenb.) Gueidan & Thüs - Thomson (1997: 645 as Verrucaria striatula)
- Xanthocarpia tominii (Savicz) Frödén, Arup & Søchting - Thomson (1997: 173 as Caloplaca tominii)
- Xanthomendoza fallax (Hepp ex Arnold) Søchting, Kärnefelt & S. Y. Kondr. - Eyerdam (1960: 110 as Xanthoria fallax), Thomson (1984: 486 as Xanthoria fallax)
- Xanthoparmelia conspersa (Ehrh. ex Ach.) Hale - Howard (1950: ), Douglas (1974: 589 as Parmelia conspersa)
- Xylographa parallela (Ach.: Fr.) Behlen & Desberger - Thomson (1997: 646 as Xylographa abietina)
- Xylographa vitiligo (Ach.) J. R. Laundon - Thomson (1997: 647)
- Xylopsora friesii (Ach. in Lilj.) Bendiksby & Timdal - Thomson (1997: 247 as Hypocenomyce friesii)