Ceramium spyridioides Feldm.-Maz. species accepted

Ceramium glandulosum (Barros-Barreto & Maggs, 2023) Barros-Barreto & Maggs, 2023 species accepted

Ceramium chathamense Feldm.-Maz. species accepted

Campylaephora sungminbooi (J.R.Hughey & G.H.Boo, 2023) Barros-Barreto & Maggs, 2023 species homotypic synonym

Celeceras novae-zelandiae (Barros-Barreto & Maggs, 2023) Barros-Barreto & Maggs, 2023 species doubtful

Pseudoceramium clarionense (Setchell & N.L.Gardner, 2023) Barros-Barreto & Maggs, 2023 species homotypic synonym

Congroceras tenuissimum Kützing species synonym

Congroceras tenuicorne Kützing species synonym

Ceramium fastgiramosum Boo & I.K.Lee species synonym

Congroceras penicillatum (Areschoug) J.Agardh species synonym

Ceramium sungminbooi J.R.Hughey & G.H.Boo species accepted

Ceramium rosenvingii H.E.Petersen species accepted

Apona echionata (J.Agardh) Kuntze, 1898 species synonym

Ceramium ciliatum var. acanthonotum Carmichael ex Harvey, 1833 variety synonym

Ceramium tenuissimum (Roth) Areschoug species synonym

Ceramium vagabunde species accepted

Ceramium nakamurai species accepted

Ceramium hirundinella (Mueller) Dujardin species accepted

Ceramium stichidiosum J.Agardh species accepted

Ceramium filicula Harv. ex Womersley species accepted

Ceramium camptum Borgesen species synonym

Ceramium templetonii Setchell & N.L.Gardner species accepted

Ceramium prostratum E.Y.Dawson species accepted

Ceramium fujianum Barros-Barreto & Maggs species accepted

Ceramium deslongchampii Chauvin ex Duby species synonym

Ceramium nanum Kuehne species accepted

Ceramium diaphanum f. strictum (Harvey) Foslie, 1893 form synonym

Ceramium villosum Kützing species synonym

Ceramium fastigiramosum Boo & I.K.Lee, 1985 species synonym

Polysiphonia polymorpha (L.) Duby, 1830 species synonym

Ceramium rubrum var. pedicellatum J.Agardh, 1912 variety synonym

Ceramium luetzelburgii var. australe A.B.Joly variety synonym

Ceramium upolense G.R.South & Skelton, 2000 species accepted

Ceramium spinosopilosum Kütz., 1863 species accepted

Gayliella taylorii (E.Y.Dawson) T.O.Cho & S.M.Boo species doubtful

Gayliella fimbriata (Setchell & N.L.Gardner) T.O.Cho & S.M.Boo species doubtful

Gayliella transversalis (Collins & Hervey) T.O.Cho & Fredericq species doubtful

Ceramium crassum species accepted

Ceramium hypnaeoides species accepted

Ceramium repens Harvey, 1863 species synonym

Ceramium deslongchampsii Chauv. ex Duby species accepted

Ceramium strictum Harvey species synonym

Ceramium agardhianum Griffiths ex Harvey, 1841 species synonym

Ceramium pellucidum (Kütz.) Rabenh., 1847 species synonym

Hormoceras catenula Kütz., 1847 species synonym

Ceramium patens Menegh., 1844 species synonym

Ceramium diaphanum var. strictum (Kütz.) Feldmann-Mazoyer, 1941 variety homotypic synonym

Ceramium clarionense Setch. & N.L.Gardner species accepted

Ceramium botryocarpum A.W.Griffiths ex Harv. species accepted

Ceramium lanciferum var. monstruosum Kütz., 1847 variety synonym

Ceramium tasmanicum (Kütz.) Womersley species accepted

Ceramium cliftonianum J.Agardh species accepted

Ceramium personatum species accepted

Ceramium procumbens species accepted

Ceramium secundatum Lyngbye species accepted

Ceramium eatonianum species accepted

Ceramium macrotrichum Feldmann-Mazoyer, 1952 species accepted

Ceramium kororensis species accepted

Ceramium tenerrimum (G.Martens) Okamura species accepted

Ceramium tenerrimum var. brevizonatum (H.E.Petersen) Feldmann-Mazoyer, 1938 variety synonym

Hormoceras tenerrimum G.Martens species synonym

Ceramium recissum Kylin species synonym

Ceramium bisporum D.L.Ballant., 1990 species accepted

Ceramium areschougii Kylin species accepted

Ceramium ornatum species accepted

Ceramium ciliatum (J.Ellis) Ducluz. species synonym

Ceramium diaphanum var. ciliatum (Ellis) Duby, 1830 variety synonym

Ceramium nudiusculum (Kütz.) Zanardini, 1847 species synonym

Ceramium japonicum species accepted

Ceramium penicillatum Areschoug species accepted

Hormoceras fruticulosum Kützing species synonym

Ceramium fruticulosum f. dichotomum H.Petersen, 1911 form synonym

Ceramium fruticulosum f. penicillatum (Aresch.) Petersen, 1908 form synonym

Ceramium penicillatum f. fasciculatum Kylin, 1907 form synonym

Ceramium fruticulosum (Kützing) J.Agardh species synonym

Ceramium vagans P.C.Silva species accepted

Ceramium subverticillatum (Grunow) Weber Bosse species accepted

Ceramium orthocladum Schiffn., 1926 species accepted

Ceramium aucklandicum Kütz. species accepted

Ceramium gardneri species accepted

Ceramium crouanianum J.Agardh, 1894 species accepted

Ceramium mazatlanense species accepted

Ceramium serpens species accepted

Ceramium subtile J.Agardh, 1851 species accepted

Ceramium nodiferum (Kützing) P.L.Crouan & H.M.Crouan species synonym

Ceramium chilense (Kütz.) P.L.Crouan & H.M.Crouan, 1878 species synonym

Ceramium cornigerum P.L.Crouan & H.M.Crouan, 1878 species synonym

Ceramium cruciatum F.S.Collins & Herv., 1917 species accepted

Ceramium sinicola species accepted

Ceramium leptocladum Schiffn., 1933 species accepted

Ceramium evermannii species accepted

Ceramium avalonae E.Y.Dawson, 1949 species accepted

Ceramium hoodii W.R.Taylor species accepted

Ceramium discorticatum Heydr. species accepted

Ceramium mucronatum species accepted

Ceramium brasiliense A.B.Joly species accepted

Ceramium arborescens J.Agardh species accepted

Ceramium vimineum J.Agardh species synonym

Ceramium rubriforme Kylin species synonym

Ceramium arborescens f. boreale Petersen, 1926 form synonym

Ceramium callipterum Mazoyer, 1938 species accepted

Ceramium circinatum (Kützing) J.Agardh species accepted

Ceramium circinatum f. densecorticatum Voronikh form synonym

Ceramium biasolethianum (Kütz.) Ardissone species synonym

Ceramium decurrens (Kützing) Kützing ex Harvey species synonym

Ceramium ramulosum Meneghini species synonym

Hormoceras decurrens Kütz., 1842 species synonym

Ceramium circinatum var. trascurrens Kütz. variety synonym

Hormoceras circinatum Kützing species synonym

Ceramium krameri G.R.South & Skelton, 2000 species accepted

Ceramium comptum Børgesen species accepted

Ceramium cimbricum H.E.Petersen species accepted

Ceramium elegans var. fastigiatum Celan & Serbanescu, 1959 variety synonym

Ceramium fastigiatum Harvey species synonym

Ceramium camouii E.Y.Dawson, 1944 species accepted

Ceramium equisetoides species accepted

Ceramium echionotum J.Agardh species accepted

Ceramium echionotum var. transcurrens (Kütz.) Batters variety synonym

Ceramium echionotum var. corticatum Mazoyer variety synonym

Acanthoceras transcurrens Kütz. species synonym

Ceramium involutum Kütz., 1849 species accepted

Ceramium rubrum var. involutum (Kütz.) Piccone, 1886 variety synonym

Ceramium uncinatum Harv. species accepted

Ceramium boydeni E.S.Gepp species accepted

Ceramium leptozonum M.A.Howe, 1918 species accepted

Ceramium cingulatum Weber Bosse, 1923 species accepted

Ceramium bertholdii Funk, 1922 species accepted

Ceramium cupulatum Womersley, 1978 species accepted

Ceramium pallidum (Nägeli ex Kütz.) Maggs & Hommers. species accepted

Ceramium armoricum P.S.Dixon & H.M.Parkes, 1968 species synonym

Trichoceras pallidum Nägeli ex Kütz., 1849 species synonym

Ceramium brevizonatum H.E.Petersen species accepted

Ceramium horridum species accepted

Ceramium affine Setch. & N.L.Gardner species accepted

Ceramium nakamurae E.Y.Dawson, 1944 species accepted

Ceramium aduncum Nakamura, 1950 species accepted

Ceramium floridanum J.Agardh, 1894 species accepted

Ceramium boergesenii H.E.Petersen species accepted

Ceramium howellii Setchell & N.L.Gardner species accepted

Ceramium siliquosum (Kützing) Maggs & Hommersand species accepted

Ceramium elegans f. longiarticulata Celan & Serbanescu form synonym

Ceramium radiculosum Grunow ex Hauck, 1867 species synonym

Ceramium elegans var. diaphanoideum Celan & Serbanescu variety synonym

Hormoceras siliquosum Kütz., 1847 species synonym

Ceramium vestitum Harv. species accepted

Ceramium luetzelburgii O.C.Schmidt species accepted

Ceramium apiculatum J.Agardh species accepted

Ceramium scandinavicum Petersen species accepted

Ceramium pacificum species accepted

Ceramium cornutum P.Dangeard, 1952 species accepted

Ceramium leutzelburgii Schmidt, 1924 species accepted

Ceramium derbesii Solier ex Kützing, 1847 species accepted

Ceramium caudatum species accepted

Ceramium septentrionale Petersen species accepted

Ceramium lenticulare Womersley species accepted

Ceramium transversale F.S.Collins & Hervey species synonym

Ceramium taylorii E.Y.Dawson species synonym

Ceramium byssoideum Harv. species synonym

Ceramium nitens (C.Agardh) J.Agardh species accepted

Ceramium rubrum var. nitens C.Agardh variety synonym

Ceramium rescissum Kylin species accepted

Ceramium fruticulosum f. rescissum (Kylin) Petersen, 1908 form synonym

Ceramium atlanticum H.E.Petersen species accepted

Ceramium californicum species accepted

Ceramium arenarium Simons, 1966 species accepted

Ceramium virgatum Roth species accepted

Ceramium rubrum var. proliferum C.Agardh, 1824 variety synonym

Ceramium nobile J.Agardh species synonym

Ceramium rubrum f. modificatum Petersen, 1908 form synonym

Ceramium rubrum f. subtypicum Petersen, 1908 form synonym

Ceramium rubrum var. pygmaeum Sonder, 1848 variety synonym

Ceramium rubrum f. irregularis-subcorticatum Petersen, 1908 form synonym

Ceramium rubrum var. pallens C.Agardh, 1811 variety synonym

Ceramium rubrum f. divaricatum Petersen, 1908 form synonym

Ceramium nodulosum (Lightfoot) Ducluzeau species synonym

Ceramium rubrum C.Agardh species synonym

Ceramium rubrum f. balticum Petersen, 1908 form synonym

Ceramium lanciferum Kütz. species synonym

Ceramium hamatispinum species accepted

Ceramium marshallense E.Y.Dawson species synonym

Ceramium gaditanum (Clemente) Cremades species accepted

Ceramium flabelligerum J.Agardh species synonym

Ceramium tenue (J.Agardh) J.Agardh, 1894 species accepted

Ceramium corniculatum Mont. species accepted

Ceramium strictoides P.L.Crouan & H.M.Crouan, 1878 species synonym

Ceramium washingtoniense species accepted

Ceramium zacae species accepted

Ceramium paniculatum Okamura, 1896 species accepted

Ceramium petitii Feldm.-Maz., 1954 species accepted

Ceramium borneense Weber Bosse species accepted

Ceramium sympodiale species accepted

Ceramium macilentum J.Agardh, 1894 species accepted

Ceramium diaphanum (Lightf.) Roth species accepted

Ceramium diaphanum f. zostericolum Petersen, 1908 form synonym

Ceramium diaphanum var. tenuissimum Roth, 1806 variety synonym

Ceramium diaphanum f. modificatum Petersen, 1908 form synonym

Ceramium tenuissimum var. tenellum G.Mazoyer variety synonym

Hormoceras nodosum Kütz., 1842 species synonym

Ceramium gracillimum (Kützing) Zanardini species synonym

Ceramium diaphanum f. medium Sjöstedt, 1928 form synonym

Ceramium nodosum (Kützing) Griffiths & Harvey species synonym

Hormoceras gracillimum Kützing species synonym

Ceramium fimbriatum Setchell & N.L.Gardner species synonym

Ceramium giacconei Cormaci & G.Furnari, 1991 species accepted

Ceramium codicola J.Agardh species accepted

Ceramium subdichotomum Weber Bosse, 1923 species synonym

Ceramium shuttleworthianum (Kützing) Rabenhorst, 1846 species homotypic synonym

Ceramium acanthonotum (Carmichael) J.Agardh species synonym

Ceramium acanthonotum f. coronatum (Kleen) Kjellman, 1880 form synonym

Ceramium obesum species accepted

Ceramium recticorticum species accepted

Ceramium tenuicorne (Kützing) Waern species accepted

Ceramium strictum f. verum Petersen, 1908 form synonym

Ceramium gobii Waern species synonym

Ceramium arachnoideum (C.Agardh) J.Agardh species synonym

Ceramium strictum subsp. tenuicorne (Kütz.) Rueness & Kornfeldt, 1992 subspecies synonym

Ceramium strictum f. stricto-tenuissimum Petersen, 1908 form synonym

Ceramium strictum f. strictoides (Petersen) Sjöstedt, 1928 form synonym

Ceramium diaphanum f. strictoides H.E.Petersen, 1908 form synonym

Ceramium diaphanum var. arachnoideum C.Agardh, 1828 variety synonym

Ceramium diaphanum f. corticatulo-strictum Kylin, 1909 form synonym

Ceramium diaphanum f. corticatulum (Kylin) Sjöstedt, 1920 form synonym

Ceramium tenuissimum var. arachnoideum (C.Agardh) Foslie, 1893 variety synonym

Ceramium circinnatum f. inferne-corticatum Lakowitz, 1907 form synonym

Ceramium corticatulum Kylin species synonym

Ceramium strictum f. corticatulo-strictum (Kylin) Sjöstedt, 1928 form synonym

Ceramium circinnatum f. spongiosum Waern, 1952 form synonym

Yoneshiguea compta (BØrgesen, 1924) Barros-Barreto, Maggs & M.A.Jaramillo, 2023 species homotypic synonym

Celeceras pusilla (Barros-Barreto & Maggs, 2023) Barros-Barreto & Maggs, 2023 species doubtful

Stirkia fujiana (Barros-Barreto & Maggs, 2023) Barros-Barreto & Maggs, 2023 species homotypic synonym

Conferva polymorpha L., 1753 species synonym

Ceramium vagabundum E.Y.Dawson species synonym

Draparnaldiana ciliata (Ellis) Grateloup, 1828 species synonym

Antithamnion divergens (J.Agardh) J.Agardh, 1896 species homotypic synonym

Gongroceras pellucidum Kütz. species synonym

Gongroceras strictum Kütz., 1842 species synonym

Gongroceras deslongchampsii (Chauv. ex Duby) Kütz., 1842 species synonym

Conferva ciliata J.Ellis, 1768 species synonym

Echinoceras nudiusculum Kütz., 1841 species synonym

Gongroceras penicillatum (Aresch.) J.Agardh, 1851 species synonym

Ceramothamnion codii H.Richards species synonym

Ceramothamnion adriaticum Schiller species synonym

Boryna nodulosa (Lightf.) Grateloup species synonym

Conferva nodulosa Lightfoot species synonym

Conferva rubra Hudson species synonym

Conferva gaditana Clemente, 1807 species synonym

Gongroceras nodiferum Kütz., 1849 species synonym

Ceramium pygmaeum Schiffner species synonym

Boryna diaphana (Lightf.) Grateloup species synonym

Gongroceras tenuissimum Kütz., 1842 species synonym

Conferva diaphana Lightfoot species synonym

Acanthoceras shuttleworthianum Kütz., 1842 species homotypic synonym

Gongroceras tenuicorne Kütz., 1841 species synonym

Ceramium botrycarpum Griffiths ex Harvey species synonym

Ceramium shuttleworthanium (Kutzing) Rabenhorst species synonym

Ceramium elegans subsp. fastigiatum Celan & Serbanescu, 1959 subspecies synonym

Ceramium diaphanum subsp. ciliatum (Ellis) Duby subspecies synonym

Ceramium botrycarpum Griffiths species homotypic synonym

Ceramium cimbricum Maggs, 1993 species synonym

Ceramium pallidum Dixon & Parkes species synonym

Ceramium proliferum f. secundatum (Lyngb.) H.E.Petersen form homotypic synonym

Ceramium botryocarpum A.W.Griffiths species homotypic synonym

Ceramium radiculosum Grunow species homotypic synonym

Trichoceras pallidum Nägeli species homotypic synonym

Ceramium filicula Harv. species homotypic synonym

Ceramium laingii Reinbold species accepted

Ceramium decurrens (Kützing) Kützing species homotypic synonym

Ceramium agardhianum Griffiths species homotypic synonym

Ceramium codii (H.Richards) Feldm.-Maz. species accepted

Ceramium pennatum J.Agardh, 1851 species synonym

Hormoceras diaphanum (Lightf.) Kütz. species synonym

Ceramium pellucidum (Kütz.) Zanardini, 1847 species synonym

Echinoceras ciliatum (Ellis) Kütz., 1842 species synonym

Ceramium fastigiatum H.E.Petersen species synonym

Ceramium rubrum Hudson species accepted

Ceramium repens Zanardini species synonym

Ceramium shuttleworthianum (Kütz.) P.C.Silva species accepted

Ceramium nudiusculum (Kütz.) Rabenh., 1847 species accepted

Gongroceras chilense Kütz., 1862 species synonym

Ceramium strictum (Kütz.) Rabenh., 1847 species homotypic synonym

Ceramium rubrum var. liebetruthii Grunow, 1844 variety synonym

Ceramium proliferum Yates, 1902 species accepted

Ceramium diaphanum Lightfoot species doubtful

Ceramium polymorphum (L.) De Candolle, 1805 species synonym

Ceramium strictum Kutzing species accepted

Ceramium rubrum f. tenue J.Agardh, 1876 form synonym

Ceramium derbesii Solier species homotypic synonym

Ceramium rubrum f. proliferum (C.Agardh) Kjellman, 1883 form synonym

Acanthoceras echionotum (J.Agardh) Kütz., 1849 species synonym

Ceramium pedicellatum J.Agardh species synonym

Chaetoceras echionotum (J.Agardh) Kütz. species synonym

Ceramium tenuissimum (Roth) J.Agardh species synonym

Ceramium ciliatum var. acanthonotum Carmichael variety homotypic synonym

Ceramium flabelliferum Kütz. species synonym

Episperma echionotum (J.Agardh) Kuntze, 1891 species synonym

Ceramium acanthonotum var. coronatum Kleen, 1874 variety synonym

Ceramium gracillimum Gobi species synonym

Ceramium gracillimum C.Agardh species accepted

Ceramium circinatum Kutzing species doubtful

Ulva confervoides L., 1753 species synonym

Ceramium divergens J.Agardh species accepted

Ceramium deslongchampii Chauvin species homotypic synonym

Ceramium deslongchampsii Chauv. species homotypic synonym