Acanthophora J.V.Lamouroux, 1813 (additional source)
Acanthophora aokii Okamura, 1934 (basis of record)
Acanthophora muscoides (Linnaeus) Bory de Saint-Vincent, 1828 (basis of record)
Acanthophora muscoides (Linnaeus) Bory de Saint-Vincent, 1828 (additional source)
Acanthophora spicifera (M.Vahl) Børgesen, 1910 (additional source)
Acetabularia J.V.Lamouroux, 1812 (additional source)
Acetabularia caliculus J.V.Lamouroux, 1824 (basis of record)
Acetabularia clavata Yamada, 1934 accepted as Parvocaulis clavatus (Yamada) S.Berger, U.Fettweiss, S.Gleissberg, L.B.Liddle, U.Richter, H.Sawitzky & G.C.Zuccarello, 2003 (additional source)
Acetabularia major G.Martens, 1866 (basis of record)
Acetabularia parvula Solms-Laubach, 1895 accepted as Parvocaulis parvulus (Solms-Laubach) S.Berger, Fettweiss, Gleissberg, Liddle, U.Richter, Sawitzky & Zuccarello, 2003 (additional source)
Acetabularia tsengiana Egerod, 1952 accepted as Parvocaulis exiguus (Solms-Laubach) S.Berger, U.Fettweiss, S.Gleissberg, L.B.Liddle, U.Richter, H.Sawitzky & G.C.Zuccarello, 2003 (basis of record)
Acinetospora Bornet, 1891 (additional source)
Acinetospora crinita (Carmichael) Sauvageau, 1899 (additional source)
Acinetosporaceae Hamel ex J. Feldmann, 1937 (basis of record)
Acrochaetium Nägeli, 1858 (additional source)
Acrochaetium arcuatum (K.M.Drew) C.K.Tseng, 1945 (basis of record)
Acrochaetium attenuatum (Rosenvinge) Hamel, 1927 accepted as Colaconema attenuatum (Rosenvinge) R.Nielsen, 1994 accepted as Acrochaetium densum (K.M.Drew) Papenfuss, 1945 accepted as Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium catenulatum M.Howe, 1914 (additional source)
Acrochaetium delisea Aziz, 1965 (basis of record)
Acrochaetium densum (K.M.Drew) Papenfuss, 1945 accepted as Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium densum (K.M.Drew) Papenfuss, 1945 accepted as Acrochaetium catenulatum M.Howe, 1914 (additional source)
Acrochaetium globosum Børgesen, 1915 (basis of record)
Acrochaetium howei (Yamada) Papenfuss, 1945 (basis of record)
Acrochaetium humile (Rosenvinge) Børgesen, 1915 (additional source)
Acrochaetium macula (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium macula (Rosenvinge) Hamel, 1927 (additional source)
Acrochaetium microscopicum (Nägeli ex Kützing) Nägeli, 1858 (additional source)
Acrochaetium minimum Collins, 1908 accepted as Colaconema minimum (Collins) Woelkerling, 1973 (basis of record)
Acrochaetium netrocarpum Børgesen, 1915 (basis of record)
Acrochaetium pacificum Kylin, 1925 (basis of record)
Acrochaetium parvulum (Kylin) Hoyt, 1920 (additional source)
Acrochaetium plumosum (K.M.Drew) G.M.Smith, 1944 (basis of record)
Acrochaetium robustum Børgesen, 1915 accepted as Colaconema robustum (Børgesen) Huisman & Woelkerling, 2018 (basis of record)
Acrochaetium robustum Børgesen, 1915 accepted as Colaconema robustum (Børgesen) Huisman & Woelkerling, 2018 (additional source)
Acrochaetium ryukyuense (Nakamura) Papenfuss, 1945 (basis of record)
Acrochaetium secundatum (Lyngbye) Nägeli, 1858 (additional source)
Acrochaetium tenuissimum (Collins) Papenfuss, 1945 (basis of record)
Acrochaetium terminale (Nakamura) Y.-P.Lee, 1987 (basis of record)
Acrochaetium vagum (K.M.Drew) C.-C.Jao, 1937 accepted as Acrochaetium arcuatum (K.M.Drew) C.K.Tseng, 1945 (basis of record)
Acrochaetium yamadae (Garbary) Y.Lee & I.K.Lee, 1988 accepted as Liagorophila endophytica Yamada, 1944 (basis of record)
Acrocystis Zanardini, 1872 (additional source)
Acrocystis nana Zanardini, 1872 (additional source)
Acrosiphonia J.Agardh, 1846 (additional source)
Acrosiphonia arcta (Dillwyn) Gain, 1912 (additional source)
Acrosiphoniaceae S. Jónsson, 1959 (basis of record)
Acrosorium Zanardini ex Kützing, 1869 (additional source)
Acrosorium ciliolatum (Harvey) Kylin, 1924 (basis of record)
Acrosorium flabellatum Yamada, 1930 (basis of record)
Acrosorium polyneurum Okamura, 1936 (basis of record)
Acrosorium venulosum (Zanardini) Kylin, 1924 (basis of record)
Acrosorium venulosum (Zanardini) Kylin, 1924 (additional source)
Acrosorium yendoi Yamada, 1930 (basis of record)
Acrothrix Kylin, 1907 (additional source)
Acrothrix pacifica Okamura & Yamada, 1932 (basis of record)
Actinotrichia Decaisne, 1842 (additional source)
Actinotrichia fragilis (Forsskål) Børgesen, 1932 (additional source)
Agarophyton Gurgel, J.N.Norris & Fredericq, 2018 (basis of record)
Agarophyton tenuistipitatum (C.F.Chang et B.-M.Xia) Gurgel, J.N.Norris & Fredericq, 2018 accepted as Gracilaria tenuistipitata C.F.Chang & B.-M.Xia, 1976 (basis of record)
Agarophyton vermiculophyllum (Ohmi) Gurgel, J.N.Norris et Fredericq, 2018 accepted as Gracilaria vermiculophylla (Ohmi) Papenfuss, 1967 (basis of record)
Aglaothamnion Feldmann-Mazoyer, 1941 (additional source)
Aglaothamnion callophyllidicola (Yamada) Boo, I.K.Lee, Rueness & Yoshida, 1991 (basis of record)
Ahnfeltia Fries, 1836 (additional source)
Ahnfeltia fastigiata (Endlicher) Makienko, 1970 (basis of record)
Ahnfeltia yinggehaiensis B.-M.Xia & Y.-Q.Zhang, 2000 (basis of record)
Ahnfeltiopsis P.C.Silva & DeCew, 1992 (additional source)
Ahnfeltiopsis flabelliformis (Harvey) Masuda, 1993 (additional source)
Ahnfeltiopsis guangdongensis B.-M.Xia & Y.-Q.Zhang, 2000 (basis of record)
Ahnfeltiopsis hainanensis B.-M.Xia & Y.-Q.Zhang, 2000 (basis of record)
Ahnfeltiopsis masudae B.-M.Xia & Y.-Q.Zhang, 2000 (basis of record)
Ahnfeltiopsis pygmaea (J.Agardh) P.C.Silva & DeCew, 1992 (basis of record)
Ahnfeltiopsis serenei (E.Y.Dawson) Masuda, 1993 (basis of record)
Akashiwo G.Hansen & Moestrup, 2000 (additional source)
Akashiwo sanguinea (K.Hirasaka) Gert Hansen & Moestrup, 2000 (basis of record)
Akashiwo sanguinea (K.Hirasaka) Gert Hansen & Moestrup, 2000 (additional source)
Alexandrium Halim, 1960 (additional source)
Alexandrium catenella (Whedon & Kofoid) Balech, 1985 (additional source)
Alexandrium leei Balech, 1985 (additional source)
Alexandrium minutum Halim, 1960 (basis of record)
Alexandrium tamarense (Lebour) Balech, 1995 (basis of record)
Alexandrium tamarense (Lebour) Balech, 1995 (additional source)
Alexandrium tamutum M.Montresor, A.Beran & U.John, 2004 (additional source)
Algirosphaera Schlauder, 1945 (additional source)
Algirosphaera robusta (Lohmann) R.E.Norris, 1984 (additional source)
Amansia J.V.Lamouroux, 1809 (additional source)
Amansia glomerata C.Agardh, 1822 (basis of record)
Amansia glomerata C.Agardh, 1822 (additional source)
Amphidinium Claperède & Lachmann, 1859 (additional source)
Amphidinium carterae Hulburt, 1957 (basis of record)
Amphiroa J.V.Lamouroux, 1812 (additional source)
Amphiroa anastomosans Weber-van Bosse, 1904 (additional source)
Amphiroa anceps (Lamarck) Decaisne, 1842 (additional source)
Amphiroa beauvoisii J.V.Lamouroux, 1816 (additional source)
Amphiroa ephedraea (Lamarck) Decaisne, 1842 (additional source)
Amphiroa foliacea J.V.Lamouroux, 1824 (additional source)
Amphiroa fragilissima (Linnaeus) J.V.Lamouroux, 1816 (additional source)
Amphiroa maletractata Simonsen, 1992 (basis of record)
Amphiroa maletractata var. constricta (Heiden) Simonsen, 2000 (basis of record)
Amphiroa zonata Yendo, 1902 accepted as Amphiroa beauvoisii J.V.Lamouroux, 1816 (basis of record)
Amphisolenia asymmetrica Kofoid, 1907 (additional source)

English ant-like flower beetles for Anthicidae Latreille, 1819
English black siphon weed [from synonym] for Polysiphonia fucoides (Hudson) Greville, 1824
English bushy berry wrack [from synonym] for Cystoseira baccata (S.G.Gmelin, 1768) P.C.Silva, 1952
Swedish fjäderslick [from synonym] for Polysiphonia fucoides (Hudson) Greville, 1824