[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Algae L. (1753) see [unranked] Algae
     Phylum Rhodophycota
       Class Rhodophyceae Thuret (1855) - red algae see Phylum Rhodophyta Wettst. (1901)
         Order Acrochaetiales Feldmann
           Family Acrochaetiaceae Melch. (1954), nom. cons.
             Genus Acrochaetium Nägeli (1858)
               01 Acrochaetium alariae (Jónsson) Bornet (1904)
               02 Acrochaetium asparagopsis (Chemin) Papenfuss (1945)
               03 Acrochaetium balticum (Rosenvinge) Aleem & Schulz (1952)
               04 Acrochaetium barbadensis (Vickers) Børgesen (1915)
               05 Acrochaetium battersianum G. Hamel (1927)
               06 Acrochaetium boergesenii Schiffner (1931)
               07 Acrochaetium bonnemaisoniae (Batters) Feldmann & G. Feldmann (1939)
               08 Acrochaetium brebneri (Batters) G. Hamel (1928)
               09 Acrochaetium caespitosum (J.Agardh) Nägeli (1862)
               10 Acrochaetium canariense Børgesen (1927)
               11 Acrochaetium catenulatum M. Howe (1914)
               12 Acrochaetium cheminii Feldmann (1954)
               13 Acrochaetium chylocladiae (Batters) Batters (1902)
               14 Acrochaetium codicolum Børgesen (1927)
               15 Acrochaetium codii (P.L. Crouan & H.M. Crouan) G. Hamel (1927)
               16 Acrochaetium collopodum (Rosenvinge) G. Hamel (1927)
               17 Acrochaetium corymbiferum (Thuret) Batters
               18 Acrochaetium crassipes (Børgesen) Børgesen
               19 Acrochaetium cymopoliae Børgesen (1927)
               20 Acrochaetium cytophagum (Rosenvinge) G. Hamel (1927)
               21 Acrochaetium daviesii (Dillwyn) Nägeli (1862)
               22 Acrochaetium duboscqii Feldmann (1939)
               23 Acrochaetium dumontiae (Rosenvinge) G. Hamel (1927)
               24 Acrochaetium efflorescens (J.Agardh) Nägeli
               25 Acrochaetium emergens (Rosenvinge) Weber-van Bosse (1921)
               26 Acrochaetium endophyticum Batters (1896)
               27 Acrochaetium endozoicum (Darbishire) Batters
               28 Acrochaetium extensum Ercegovic
               29 Acrochaetium gracile Børgesen (1915)
               30 Acrochaetium gynandrum (Rosenvinge) G. Hamel (1927)
               31 Acrochaetium hallandicum (Kylin) G. Hamel (1927) see Colaconema hallandicum (Kylin) Afonso-Carillo, Sansón, Sangil & Díaz-Villa (2007)
               32 Acrochaetium hauckii Schiffner (1916)
               33 Acrochaetium immersum (Rosenvinge) G. Hamel (1927)
               34 Acrochaetium inclusum (Levring) Papenfuss (1945)
               35 Acrochaetium incrassatum Ercegovic
               36 Acrochaetium infestans M. Howe & Hoyt
               37 Acrochaetium kylini G. Hamel (1927)
               38 Acrochaetium lenormandii (Suhr ex Kütz.) Nägeli
               39 Acrochaetium leptonema (Rosenvinge) Børgesen (1915)
               40 Acrochaetium liagorae Børgesen (1915)
               41 Acrochaetium lorrain-smithiae (Lyle) L. Newton (1931)
               42 Acrochaetium macula (Rosenvinge) G. Hamel (1927)
               43 Acrochaetium mediterraneum (Levring) Boudouresque (1970)
               44 Acrochaetium microfilum C.C. Jao (1936)
               45 Acrochaetium microscopicum (Nägeli ex Kütz.) Nägeli (1862)
               46 Acrochaetium minutum (Suhr) G. Hamel (1927)
               47 Acrochaetium mirabilis (Suhr) Nägeli (1862)
               48 Acrochaetium molinieri Coppejans & Boudouresque (1976)
               49 Acrochaetium moniliforme (Rosenvinge) Børgesen (1915)
               50 Acrochaetium naumannii (Askenasy) Askenasy
               51 Acrochaetium nemalii (De Not. ex L. Dufour) Bornet
               52 Acrochaetium nemalionis (De Not. ex L. Dufour) Bornet (1904)
               53 Acrochaetium nitophylli (Levring) Papenfuss (1945)
               54 Acrochaetium occidentale Børgesen (1915)
               55 Acrochaetium pallens (Zanardini) Nägeli (1862)
               56 Acrochaetium parvulum (Kylin) Hoyt (1920)
               57 Acrochaetium pulchellum Børgesen
               58 Acrochaetium radiatum C.C. Jao (1936)
               59 Acrochaetium reductum (Rosenvinge) G. Hamel (1927)
               60 Acrochaetium robustum Børgesen (1915)
               61 Acrochaetium rosulatum (Rosenvinge) Papenfuss
               62 Acrochaetium sanctae-mariae (Darbishire) G. Hamel
               63 Acrochaetium savianum (Meneghini) Nägeli (1862)
               64 Acrochaetium secundatum (Lyngbye) Nägeli (1858)
               65 Acrochaetium seiriolanum (Gibson) Rosenvinge (1924)
               66 Acrochaetium sparsum (Carmichael ex Harvey) Nägeli (1862)
               67 Acrochaetium stilophorae (Levring) Kylin (1944)
               68 Acrochaetium subpinnatum Bornet ex G. Hamel
               69 Acrochaetium subseriatum Børgesen
               70 Acrochaetium subtilissimum (Kütz.) G. Hamel (1927)
               71 Acrochaetium trifilum (Buffham) Batters
               72 Acrochaetium unifilum C.C. Jao (1936)
               73 Acrochaetium virgatulum (Harvey) Batters (1902)