Acinetospora Bornet, 1891 (additional source)
Acinetospora crinita (Carmichael) Sauvageau, 1899 (additional source)
Acinetosporaceae Hamel ex J. Feldmann, 1937 (basis of record)
Acrochaete N.Pringsheim, 1862 accepted as Ulvella P.L.Crouan & H.M.Crouan, 1859 (additional source)
Acrochaete leptochaete (Huber) R.Nielsen, 1983 accepted as Ulvella leptochaete (Huber) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete viridis (Reinke) R.Nielsen, 1979 accepted as Ulvella viridis (Reinke) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete wittrockii (Wille) R.Nielsen, 1983 accepted as Ulvella wittrockii (Wille) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrosiphonia J.Agardh, 1846 (additional source)
Acrosiphonia arcta (Dillwyn) Gain, 1912 (additional source)
Acrosiphoniaceae S. Jónsson, 1959 (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 monilatum (J.F.Howell) Balech, 1995 (additional source)
Alsidium C.Agardh, 1827 (additional source)
Alsidium corallinum C.Agardh, 1827 (additional source)
Antithamnieae Hommersand, 1963 (basis of record)
Antithamnion Nägeli, 1847 (additional source)
Antithamnion cruciatum (C.Agardh) Nägeli, 1847 (additional source)
Antithamnion heterocladum Funk, 1955 (additional source)
Antithamnion tenuissimum (Hauck) Schiffner, 1915 (basis of record)
Antithamnion tenuissimum (Hauck) Schiffner, 1915 (additional source)
Arthrocladia Duby, 1830 (additional source)
Arthrocladia villosa (Hudson) Duby, 1830 (additional source)
Bangia Lyngbye, 1819 (additional source)
Bangia fuscopurpurea (Dillwyn) Lyngbye, 1819 (additional source)
Blastophysa Reinke, 1889 (additional source)
Blastophysa polymorpha Kjellmann, 1897 accepted as Blastophysa rhizopus Reinke, 1889 (basis of record)
Blastophysa rhizopus Reinke, 1889 (additional source)
Blidingia Kylin, 1947 (additional source)
Blidingia marginata (J.Agardh) P.J.L.Dangeard ex Bliding, 1963 (additional source)
Blidingia minima (Nägeli ex Kützing) Kylin, 1947 (additional source)
Bolbocoleon Pringsheim, 1863 (additional source)
Bolbocoleon piliferum Pringsheim, 1862 (basis of record)
Bolbocoleon piliferum Pringsheim, 1862 (additional source)
Bornetia Thuret, 1855 (additional source)
Bornetia secundiflora (J.Agardh) Thuret, 1855 (additional source)
Brongniartella Bory de Saint-Vincent, 1822 (additional source)
Brongniartella byssoides (Goodenough & Woodward) F.Schmitz, 1893 accepted as Vertebrata byssoides (Goodenough & Woodward) Kuntze, 1891 (additional source)
Bryopsidineae (basis of record)
Bryopsidophyceae accepted as Ulvophyceae (basis of record)
Bryopsis J.V.Lamouroux, 1809 (additional source)
Bryopsis adriatica (J.Agardh) Frauenfeld, 1854 accepted as Bryopsis cupressina var. adriatica (J.Agardh) M.J.Wynne, 2005 (additional source)
Bryopsis cupressina J.V.Lamouroux, 1809 (additional source)
Bryopsis cupressina var. adriatica (J.Agardh) M.J.Wynne, 2005 (basis of record)
Bryopsis duplex De Notaris, 1844 (additional source)
Bryopsis hypnoides J.V.Lamouroux, 1809 (additional source)
Bryopsis plumosa (Hudson) C.Agardh, 1823 (additional source)
Callithamnieae Schmitz, 1889 (basis of record)
Callithamnioideae De Toni, 1903 (basis of record)
Callithamnion Lyngbye, 1819 (additional source)
Callithamnion corymbosum (Smith) Lyngbye, 1819 (additional source)
Callithamnion granulatum (Ducluzeau) C.Agardh, 1828 (additional source)
Capsosiphon Gobi, 1879 (additional source)
Capsosiphon fulvescens (C.Agardh) Setchell & N.L.Gardner, 1920 (additional source)
Carradoriella P.C.Silva, 1996 (additional source)
Carradoriella denudata (Dillwyn) Savoie & G.W.Saunders, 2019 (basis of record)
Carradoriella elongata (Hudson) Savoie & G.W.Saunders, 2019 (basis of record)
Caulerpa J.V.Lamouroux, 1809 (additional source)
Caulerpa prolifera (Forsskål) J.V.Lamouroux, 1809 (additional source)
Ceramieae (Dumortier) Schmitz, 1889 (basis of record)
Ceramium Roth, 1797 (additional source)
Ceramium ciliatum (J.Ellis) Ducluzeau, 1806 (additional source)
Ceramium cimbricum H.E.Petersen, 1924 (additional source)
Ceramium circinatum (Kützing) J.Agardh, 1851 (additional source)
Ceramium codii (H.Richards) Mazoyer, 1938 accepted as Stirkia codii (H.Richards) Barros-Barreto & Maggs, 2023 (basis of record)
Ceramium codii (H.Richards) Mazoyer, 1938 accepted as Stirkia codii (H.Richards) Barros-Barreto & Maggs, 2023 (additional source)
Ceramium deslongchampsii Chauvin ex Duby, 1830 (additional source)
Ceramium diaphanum (Lightfoot) Roth, 1806 (additional source)
Ceramium echionotum J.Agardh, 1844 (additional source)
Ceramium flaccidum (Harvey ex Kützing) Ardissone, 1871 accepted as Gayliella flaccida (Harvey ex Kützing) T.O.Cho & L.J.McIvor, 2008 (additional source)
Ceramium gaditanum (Clemente) Cremades, 1990 (additional source)
Ceramium rubrum C.Agardh, 1811 accepted as Ceramium virgatum Roth, 1797 (additional source)
Ceramium secundatum Lyngbye, 1819 (additional source)
Ceramium siliquosum (Kützing) Maggs & Hommersand, 1993 (additional source)
Ceramium tenerrimum (G.Martens) Okamura, 1921 accepted as Pseudoceramium tenerrimum (G.Martens) Barros-Barreto & Maggs, 2023 (basis of record)
Ceramium tenerrimum (G.Martens) Okamura, 1921 accepted as Pseudoceramium tenerrimum (G.Martens) Barros-Barreto & Maggs, 2023 (additional source)
Ceramium virgatum Roth, 1797 (additional source)
Chaetomorpha Kützing, 1845 (additional source)
Chaetomorpha aerea (Dillwyn) Kützing, 1849 (additional source)
Chaetomorpha crassa (C.Agardh) Kützing, 1845 (additional source)
Chaetomorpha gracilis Kützing, 1845 (additional source)
Chaetomorpha ligustica (Kützing) Kützing, 1849 (additional source)
Chaetomorpha linum (O.F.Müller) Kützing, 1845 (additional source)
Chaetomorpha mediterranea (Kützing) Kützing, 1849 (basis of record)
Chaetomorpha vieillardii (Kützing) M.J.Wynne, 2011 (basis of record)
Chaetomorpha zernovii Woronichin, 1925 (basis of record)
Chaetomorpha zernovii Woronichin, 1925 (additional source)
Chaetopeltis orbicularis Berthold, 1878 (additional source)
Chlorellales (basis of record)
Chlorophyceae (basis of record)
Chondria C.Agardh, 1817 (additional source)
Chondria boryana (De Notaris ex J.Agardh) De Toni, 1903 (additional source)
Chondria capillaris (Hudson) M.J.Wynne, 1991 (additional source)
Chondria dasyphylla (Woodward) C.Agardh, 1817 (additional source)
Chondrophycus (J.Tokida & Y.Saito) Garbary & J.T.Harper, 1998 (additional source)
Chondrophycus paniculatus (C.Agardh) G.Furnari, 2000 accepted as Chondrophycus thuyoides (Kützing) G.Furnari, 2001 accepted as Palisada thuyoides (Kützing) Cassano, Sentíes, Gil-Rodríguez & M.T.Fujii, 2009 (additional source)
Chondrophycus papillosus (C.Agardh) D.J.Garbary & J.T.Harper, 1998 accepted as Palisada perforata (Bory) K.W.Nam, 2007 (additional source)
Chondrophycus thuyoides (Kützing) G.Furnari, 2001 accepted as Palisada thuyoides (Kützing) Cassano, Sentíes, Gil-Rodríguez & M.T.Fujii, 2009 (basis of record)

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