• Species: Ochrolechia upsaliensis (L.) A. Massal.
• Remark: excluded as misidentification: re-identified as Ochrolechia szatalaensis
• Fungus type: lichenized
• Treatment in Estonia: misidentification

• Species: Omphalina umbellifera (L.) Quél.
• Remark: see: Lichenomphalia umbellifera (L.) Redhead, Lutzoni, Moncalvo & Vilgalys
• Fungus type: lichenized
• Treatment in Estonia: synonym
• turba-sõlgsamblik

• Species: Opegrapha atra Pers.
• Remark: See: Arthonia atra
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha culmigena Lib.
• Remark: see: Alyxoria culmigena (Lib.) Ertz; earlier under Opegrapha herbarum Mont.
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha herbarum Mont.
• Remark: see: Alyxoria culmigera (Lib.) Ertz; earlier also under Opegrapha culmigena Lib.
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha mougeotii A. Massal.
• Remark: See: Alyxoria mougeotii
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha niveoatra (Borrer) J.R. Laundon
• Remark: earlier under Opegrapha vulgata var. subsiderella Nyl.
• Fungus type: lichenized
• Treatment in Estonia: certain

• Species: Opegrapha ochrocheila Nyl.
• Remark: See: Alyxoria ochrocheila
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha rufescens Pers.
• Remark: See: Pseudoschismatomma rufescens
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha rupestris Pers.
• Remark:
• Fungus type: lichenicolous
• Treatment in Estonia: certain

• Species: Opegrapha sorediifera P. James
• Remark: See: Zwackhia sorediifera
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha varia Pers.
• Remark: See: Alyxoria varia
• Fungus type: lichenized
• Treatment in Estonia: synonym
• härma-kiiriksamblik

• Species: Opegrapha viridis (Pers. ex Ach.) Behlen & Desberger
• Remark: See: Zwackhia viridis
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha vulgata var. subsiderella Nyl.
• Remark: see: Opegrapha niveoatra
• Fungus type: lichenized
• Treatment in Estonia: synonym

• Species: Opegrapha vulgata Ach.
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain

• Species: Opegrapha zwackhii (A. Massal. ex Zwackh) Källsten
• Remark: See: Phacographa zwackhii
• Fungus type: lichenicolous
• Treatment in Estonia: synonym

• Species: Ophioparma ventosa (L.) Norman
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain

• Species: Pachyphiale fagicola (Hepp) Zwackh
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain

• Species: Pannaria leucophaea (Vahl) P.M. Jørg.
• Remark: see: Vahliella leucophaea; earlier also under Fuscopannaria leucophaea
• Fungus type: lichenized
• Treatment in Estonia: synonym
• kalju-sinisamblik

• Species: Pannaria pezizoides (Weber) Trevis.
• Remark: see: Protopannaria pezizoides
• Fungus type: lichenized
• Treatment in Estonia: synonym
• harilik sinisamblik

• Species: Parmelia ernstiae Feuerer & A. Thell
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain
• Ernsti lapiksamblik

• Species: Parmelia fraudans (Nyl.) Nyl.
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain
• petlik lapiksamblik

• Species: Parmelia omphalodes (L.) Ach.
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain
• kriips-lapiksamblik

• Species: Parmelia saxatilis (L.) Ach.
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain
• kivi-lapiksamblik

• Species: Parmelia submontana Nádv. ex Hale
• Remark:
• Fungus type: lichenized
• Treatment in Estonia: certain
• ripp-lapiksamblik

• Species:
• Remark:
• Fungus type:
• Treatment in Estonia: