Oc Genus:
Ocellularia G. Mey. 1825 (Lichens) •
Ocellularia capensis var.
feracior Zahlbr. 1932 •
Ocellularia capensis var.
leiothallina Zahlbr. 1932 •
Ocellularia cavata (Ach.) Müll. Arg. 1882 •
Ocellularia diploschistoides Zahlbr. 1932 •
Ocellularia galactina Zahlbr. 1932 •
Ocellularia henatomma (Ach.) Müll. Arg. 1887 Genus:
Ochrolechia A.Massal. (1852) (Lichens) •
Ochrolechia africana Vain. 1926 •
Ochrolechia africana Vain. 1926 •
Ochrolechia pallescens (L.) A. Massal. 1853 •
Ochrolechia parella (L.) A. Massal. 1852 Genus:
Octaviania Vittad. 1831 •
Octaviania africana Lloyd 1922 accepted as
Neosecotium africanum (Lloyd) Singer & A.H. Sm., (1960) •
Octaviania carnea (Wallr.) Corda 1854 accepted as
Hydnangium carneum Wallr., (1839) •
Octaviania flava G.H.Cunn. accepted as
Stephanospora flava (Rodway) G.W. Beaton, Pegler & T.W.K. Young, (1985)
Od Genus:
Odontia Pers. 1794 •
Odontia arguta (Fr.) Quél. 1888 accepted as
Hyphodontia arguta (Fr.) J. Erikss., (1958) •
Odontia knysnana Van der Byl 1934 accepted as
Xylodon knysnanus (Van der Byl) Hjortstam & Ryvarden, (2009) •
Odontia saccharicola Burt 1917 accepted as
Resinicium saccharicola (Burt) Nakasone, (2000)
Oi Genus:
Oidiopsis Scalia 1902 accepted as
Leveillula G. Arnaud, (1921) •
Oidiopsis taurica (Lév.) E.S. Salmon 1906 accepted as
Leveillula taurica (Lév.) G. Arnaud, (1921) Genus:
Oidium Link 1824 •
Oidium abelmoschi Thüm. 1878 accepted as
Fibroidium abelmoschi (Thüm.) U. Braun & R.T.A. Cook, (2012) •
Oidium chrysanthemi Rabenh. 1853 accepted as
Golovinomyces chrysanthemi (Rabenh.) M. Bradshaw, U. Braun, Meeboon & S. Takam., (2017) •
Oidium erysiphoides Fr. (1832), accepted as
Golovinomyces biocellatus (Ehrenb.) V.P. Heluta, (1988) •
Oidium farinosum Cooke (1887), accepted as
Podosphaera leucotricha (Ellis & Everh.) E.S. Salmon, (1900) •
Oidium hortensiae Jørst. 1925 accepted as
Pseudoidium hortensiae (Jørst. ex S. Blumer) U. Braun & R.T.A. Cook, (2012) •
Oidium lactis Fresen. 1850 accepted as
Dipodascus geotrichum (E.E. Butler & L.J. Petersen) Arx, (1977) •
Oidium leuconium Desm. 1829 accepted as
Podosphaera pannosa (Wallr.) de Bary, (1870) •
Oidium lycopersici Cooke & Massee, (1888) [as
lycopersicum] accepted as
Golovinomyces lycopersici (Cooke & Massee) L. Kiss, (2019) •
Oidium mangiferae Berthet 1914 •
Oidium quercinum Thüm. 1878 accepted as
Erysiphe alphitoides (Griffon & Maubl.) U. Braun & S. Takam., (2000) •
Oidium tabaci Thüm. 1879 accepted as
Golovinomyces cichoracearum (DC.) V.P. Heluta [as 'cichoraceorum'], (1988) •
Oidium tuckeri Berk. 1847 accepted as
Erysiphe necator Schwein., [1834] •
Oidium verbenae Thüm. & P.C. Bolle 1885 accepted as
Acrosporium verbenae (Thüm. & P.C. Bolle) J.A. Stev., (1975) •
Oidium sp.
Ol Genus:
Olpidiopsis Cornu 1872 •
Olpidiopsis ricciae du Plessis 1933 Genus:
Oligostroma Syd. & P. Syd. 1914 accepted as
Ramularia Unger, (1833) •
Oligostroma maculiformis (G. Winter) Doidge 1921 accepted as
Teratosphaeria maculiformis (G. Winter) Joanne E. Taylor & Crous, (1999) •
Oligostroma proteae Syd. & P. Syd. 1914 accepted as
Mycosphaerella proteae (Syd. & P. Syd.) Arx, (1962)
Om Genus:
Ombrophila Fr. 1849 •
Ombrophila nigrescens Henn. 1902 Genus:
Omphalia (Fr.) Gray 1821, accepted as
Omphalina Quél., (1886) •
Omphalia bulbosa Bres. 1920 •
Omphalia glaucophylla Gill. possibly (Lasch) Sacc. 1887 •
Omphalia griseopallida Quel. possibly (Desm.) P. Karst. 1879 accepted as
Arrhenia griseopallida (Desm.) Watling, [1988] •
Omphalia integrella Quel. possibly (Pers.) P. Kumm. 1871 accepted as
Delicatula integrella (Pers.) Fayod, (1889) •
Omphalia linopus (Kalchbr.) Sacc. 1887 •
Omphalia micromeles (Berk. & Broome) Sacc. 1887 •
Omphalia oniscus (Fr.) Gillet 1876 accepted as
Arrhenia oniscus (Fr.) Redhead, Lutzoni, Moncalvo & Vilgalys [as
onisca], (2002) •
Omphalia pallescens Bres. 1920 accepted as
Clitocybe torrendii Pegler, (1966) •
Omphalia paurophylla (Berk.) Sacc. 1891 •
Omphalia polypus (Kalchbr.) Sacc. 1887 accepted as
Marasmius polypus (Kalchbr.) D.A. Reid, (1975) •
Omphalia rustica (Fr.) Quél. 1872, accepted as
Arrhenia rustica (Fr.) Redhead, Lutzoni, Moncalvo & Vilgalys, (2002) •
Omphalia scyphoides Quel. possibly (Fr.) P. Kumm. 1871, accepted as
Clitopilus scyphoides (Fr.) Singer, (1946) •
Omphalia syndesmia (Kalchbr.) Sacc. 1887; •
Omphalia umbellifera Quel. var.
cinnabarina Berk.* Genus:
Omphalaria Durieu & Mont. 1847 (?) accepted as
Thyrea A. Massal., (1856) •
Omphalaria minuscula (Nyl.) Vain. 1901 Genus:
Omphalodium Meyen & Flot. 1843 (?) (Lichens) •
Omphalodium hottentottum (Ach.) Flot. 1843 accepted as
Xanthoparmelia hottentotta (Ach.) A. Thell, Feuerer, Elix & Kärnefelt, J. Hattori (2006) •
Omphalodium hottentottum var.
phalacrum Hue 1900 •
Omphalodium mutabile (Taylor) Minks 1900;
On Genus:
Oncospora Kalchbr. 1880 •
Oncospora bullata Kalchbr. & Cooke 1880 •
Oncospora viridans Kalchbr. & Cooke 1880
Oo Genus:
Oospora Wallr. 1833, accepted as
Oidium Link, (1824) •
Oospora citri-aurantii (Ferraris) Sacc. & P. Syd. 1902accepted as
Dipodascus geotrichum (E.E. Butler & L.J. Petersen) Arx, 336 (1977) •
Oospora fimicola (Costantin & Matr.) Cub. & Megliola 1903, accepted as
Scopulariopsis coprophila (Cooke & Massee) W. Gams, (1971) •
Oospora fusidium (Thüm.) Sacc. & Voglino 1886 •
Oospora lactis (Fresen.) Sacc. 1886 accepted as
Dipodascus geotrichum (E.E. Butler & L.J. Petersen) Arx, (1977) •
Oospora pustulans M.N. Owen & Wakef. 1919 [as
pustularis] accepted as
Polyscytalum pustulans (M.N. Owen & Wakef.) M.B. Ellis, (1976) •
Oospora scabies Thaxt. 1892 Genus:
Oothecium Speg. 1918, accepted as
Asterostomella Speg., (1886) •
Oothecium consimile Syd. 1930 •
Oothecium macarangae Petr. 1928 accepted as
Capnodiastrum macarangae (Petr.) Petr., (1952) •
Oothecium stylosporum (Cooke) Doidge 1942 accepted as
Capnodiastrum stylosporum (Cooke) Petr., (1952)
Op Genus:
Opegrapha (Lichens) •
Opegrapha adpicta Zahlbr. 1932 •
Opegrapha agelaea Fée 1837 •
Opegrapha atra Pers. 1794 accepted as
Arthonia atra (Pers.) A. Schneid., (1898) •
Opegrapha bacillosa Zahlbr. 1936 •
Opegrapha bonplandi Fée 1825 •
Opegrapha capensis Müll. Arg. 1888 •
Opegrapha diagraphoides Nyl. 1869 •
Opegrapha diaphorella Stizenb. 1891 •
Opegrapha emersa Müll. Arg. 1887 accepted as
Lecanographa lyncea (Sm.) Egea & Torrente, (1994) •
Opegrapha exiguella Zahlbr. 1936 [as
exigualla] •
Opegrapha exornata Zahlbr. •
Opegrapha interalbata Nyl. 1867 •
Opegrapha lactifera Zahlbr. 1936 •
Opegrapha lyncea (Sm.) Borrer ex Hook. 1833 accepted as
Lecanographa lyncea (Sm.) Egea & Torrente, (1994) •
Opegrapha medusulina Nyl. 1895 •
Opegrapha menyharthii Müll. Arg. 1893 •
Opegrapha parvula Nyl. 1876 •
Opegrapha prosodea var.
microcarpella Zahlbr. 1936 •
Opegrapha quaternella Nyl. f.
congesta Stizenb.* •
Opegrapha scripta (L.) Ach. 1803 accepted as
Graphis scripta (L.) Ach., (1809) •
Opegrapha semiatra Müll. Arg. 1886 •
Opegrapha signatella Vain. 1926 •
Opegrapha tapetica Zahlbr. 1932. •
Opegrapha ulcerata Müll. Arg. 1895 •
Opegrapha zanei A. Massal. 1861 Genus:
Ophiobolus Riess 1854 •
Ophiobolus cariceti (Berk. & Broome) Sacc. (1883), accepted as
Gaeumannomyces graminis var.
graminis (Sacc.) Arx & D.L. Olivier, (1952) •
Ophiobolus graminis (Sacc.) Sacc. (1881), accepted as
Gaeumannomyces graminis var.
graminis (Sacc.) Arx & D.L. Olivier, (1952) •
Ophiobolus cariceti (Berk. & Broome) Sacc. 1883, accepted as
Gaeumannomyces graminis (Sacc.) Arx & D.L. Olivier, (1952) •
Ophiobolus stipae Doidge 1941 •
Ophiobolus urticae (Rabenh.) Sacc. 1883 accepted as
Pseudoophiobolus erythrosporus (Riess) Phookamsak, Wanas., & K.D. Hyde, (2017) Genus:
Ophiodothella (Henn.) Höhn. 1910 •
Ophiodothella edax (Berk. & Broome) Höhn. 1910 •
Ophiodothella liebenbergii Doidge 1942
Or Genus:
Orbilia Fr. 1836 •
Orbilia rubella (Pers.) P. Karst. 1871 •
Orbilia xanthostigma (Fr.) Fr. 1849 Family:
Orbiliaceae Nannf. 1932
Ot Genus:
Otthia Nitschke ex Fuckel 1870 •
Otthia deformans Pat. 1918
Ov Genus:
Ovularia Sacc. 1880, accepted as
Ramularia Unger, (1833) •
Ovularia bistorta (Fuckel) Sacc. 1886 accepted as
Ramularia bistortae Fuckel, (1870) •
Ovularia lolii Volkart 1903 accepted as
Ramularia lolii (Volkart) U. Braun, (1988) Genus:
OvulariopsisPat. & Har. 1900 •
Ovulariopsis moricola Delacr. 1903 •
Ovulariopsis papayae Van der Byl 1921 accepted as
Phyllactinia papayae (Van der Byl) U. Braun, (2016) •
Ovulariopsis sp. ==P==