Usnea amblyoclada
Usnea baileyi
Usnea cavernosa
Usnea ceratina
Usnea cornuta
Usnea dasopoga
Usnea dimorpha
Usnea diplotypus
Usnea esperantiana
Usnea filipendula (see Usnea dasopoga)
Usnea flavocardia
Usnea fragilescens
Usnea glabrata
Usnea hesperina (see Usnea subgracilis)
Usnea hirta
Usnea intermedia
Usnea lapponica (see Usnea perplexans)
Usnea longissima (see Dolichousnea longissima)
Usnea mutabilis
Usnea occidentalis
Usnea parvula
Usnea perplectata (see Usnea baileyi)
Usnea perplexans
Usnea rubicunda
Usnea scabrata
Usnea silesiaca
Usnea sphacelata (or U. lambii)
Usnea strigosa
Usnea subfloridana
Usnea subgracilis
Usnea subscabrosa
Usnea substerilis cfr. (see Usnea perplexans)
Usnea trichodea
Usnea wirthii (see Usnea flavocardia)
Usnea (unidentified species)

Usnocetraria oakesiana

Vahliella leucophaea
Vahliella saubinetti (see Fuscopannaria pacifica)

Varicellaria velata

Verrucaria calciseda (see Bagliettoa calciseda)
Verrucaria aethiobola
Verrucaria epimaura
Verrucaria epimaura with Hydropunctaria maura
Verrucaria inficiens
Verrucaria latebrosa
Verrucaria margacea
Verrucaria maura (see Hydropunctaria maura)
Verrucaria muralis
Verrucaria nigrescens
Verrucaria subdivisa
Verrucaria (unidentified species)

Vestergrenopsis elaeina (see Tingiopsidium elaeinum)
Vestergrenopsis isidiata (see Tingiopsidium isidiatum)
Vestergrenopsis sonomensis (see Tingiopsidium sonomense)

Viridothelium virens

Vulpicida canadensis
Vulpicida juniperina
Vulpicida pinastri
Vulpicida tilesii (see Vulpicida juniperina)
Vulpicida viridis

Willeya diffractella

Xanthocarpia crenulatella
Xanthocarpia crenulatella (group)
Xanthocarpia feracissima
Xanthocarpia tominii

Xanthomendoza fallax
Xanthomendoza fulva
Xanthomendoza galericulata
Xanthomendoza hasseana
Xanthomendoza montana
Xanthomendoza oregana
Xanthomendoza trachyphylla
Xanthomendoza ulophyllodes

Xanthoparmelia ahtii
Xanthoparmelia ajoensis
Xanthoparmelia atticoides
Xanthoparmelia brunella
Xanthoparmelia californica
Xanthoparmelia camtschadalis
Xanthoparmelia chiricahuensis
Xanthoparmelia chlorochroa
Xanthoparmelia coloradoensis
Xanthoparmelia conspersa
Xanthoparmelia cumberlandia
Xanthoparmelia hypomelaena
Xanthoparmelia idahoensis
Xanthoparmelia lavicola
Xanthoparmelia lineola
Xanthoparmelia loxodes
Xanthoparmelia maricopensis
Xanthoparmelia mexicana
Xanthoparmelia mougeotii
Xanthoparmelia neochlorochra
Xanthoparmelia nigropsoromifera
Xanthoparmelia norchlorochra
Xanthoparmelia novomexicana
Xanthoparmelia plittii
Xanthoparmelia schmidtii
Xanthoparmelia stenophylla
Xanthoparmelia subhosseana
Xanthoparmelia subramigera
Xanthoparmelia substenophylloides
Xanthoparmelia verruculifera
Xanthoparmelia weberi
Xanthoparmelia wyomingica
Xanthoparmelia (unidentified species)

Xanthoria candelaria (see Polycauliona candelaria)
Xanthoria elegans (see Rusavskia elegans)
Xanthoria fallax (see Xanthomendoza fallax)
Xanthoria fulva (see Xanthomendoza fulva)
Xanthoria hasseana (see Xanthomendoza hasseana)
Xanthoria montana (see Xanthomendoza montana)
Xanthoria oregana (see Xanthomendoza oregana)
Xanthoria parietina
Xanthoria pollinarioides (see Polycauliona pollinarioides)
Xanthoria polycarpa (see Polycauliona polycarpa)
Xanthoria sorediata (see Rusavskia sorediata)
Xanthoria ulophyllodes (see Xanthomendoza ulophyllodes)
Xanthoria (in the former, broad sense) unidentified species

Xanthosyne sharnoffiorum
Xanthosyne granularis R.C. Harris, ined.
(see Lichen Mixtures on Bark # 28)
Xanthosyne sp. (not yet published)

Xylographa hians
Xylographa opegraphella
Xylographa parallela
Xylographa vitiligo

Zwackhia viridis