• Dasya C.Agardh, 1824
• Dasya abbottiana D.L.Ballantine & N.E.Aponte, 2004
• Dasya abyssicola E.Y.Dawson, 1949 accepted as Dasya sinicola var. abyssicola (Dawson) Dawson, 1963
• Dasya acanthophora Montagne, 1841 accepted as Polysiphonia flexella (C.Agardh) J.Agardh, 1842
• Dasya adela Heggøy, Rueness & Sjøtun, 2016
• Dasya adhaerens Yamada, 1944 accepted as Dasya anastomosans (Weber Bosse) M.J.Wynne, 2002
• Dasya adunca J.Agardh, 1890 accepted as Thaumatella adunca (J.Agardh) Parsons & Womersley, 1998
• Dasya anastomosans (Weber Bosse) M.J.Wynne, 2002
• Dasya antillarum (M.A.Howe) A.J.K.Millar, 1996
• Dasya aperta (Weber Bosse) A.J.K.Millar, 1996
• Dasya apiculata (C.Agardh) J.Agardh, 1863
• Dasya arbuscula (R.Brown ex Dillwyn) C.Agardh, 1828 accepted as Aglaothamnion sepositum (Gunnerus) Maggs & Hommersand, 1993 accepted as Gaillona seposita (Gunnerus) Athanasiadis, 2016
• Dasya arbuscula var. caespitosa J.Agardh
• Dasya arbuscula var. minor E.C.Oliveira, 1969
• Dasya arbuscula var. villosa (Kützing) Hauck
• Dasya archeri Harvey, 1859 accepted as Dasyclonium flaccidum (Harvey) Kylin, 1956
• Dasya atactica J. Agardh, 1890 represented as Dasya atactica J.Agardh, 1890
• Dasya atactica J.Agardh, 1890
• Dasya atropurpurea Vroom, 2005
• Dasya australis J.Agardh, 1863 accepted as Heterosiphonia australis (J.Agardh) De Toni, 1903
• Dasya baillouviana (S.G.Gmelin) Montagne, 1841 accepted as Dasya pedicellata (C.Agardh) C.Agardh, 1824
• Dasya baillouviana var. nudicaulis (E.Y.Dawson) J.N.Norris & K.E.Bucher, 1976
• Dasya baillouviana var. stanfordiana (Farlow) J.N.Norris & K.E.Bucher, 1976 accepted as Dasya pedicellata subsp. stanfordiana (Farlow) J.N.Norris & Bucher, 2014
• Dasya baldockii Parsons & Womersley, 1998
• Dasya berkeleyi (Montagne) J.Agardh, 1863 accepted as Heterosiphonia berkeleyi Montagne, 1842
• Dasya binghamiae A.J.K.Millar, 1996
• Dasya bolbochaete Harvey, 1844 accepted as Doxodasya bolbochaete (Harvey) Falkenberg, 1901
• Dasya boninensis M.Masuda, A.Kurihara & K.Kogame, 2007
• Dasya brasiliensis E.C.Oliveira Filho & Y.Y.Braga, 1971
• Dasya californica N.L.Gardner, 1927 accepted as Dasya sinicola var. californica (Gardner) Dawson, 1963
• Dasya calliptera Sonder ex Kützing, 1864 accepted as Heterosiphonia australis (J.Agardh) De Toni, 1903
• Dasya callithamnium (Sonder) Harvey, 1855 accepted as Heterosiphonia callithamnium (Sonder) Falkenberg, 1901
• Dasya capillaris J.D.Hooker & Harvey, 1847
• Dasya caraibica Børgesen, 1919
• Dasya cattloviae Gatty, 1863 accepted as Dasya punicea (Zanardini) Meneghini ex Zanardini, 1841
• Dasya ceramioides Harvey, 1844
• Dasya cernua A.J.K.Millar, 1990
• Dasya cervicornis J.Agardh, 1841 accepted as Eupogodon planus (C.Agardh) Kützing, 1845
• Dasya chilensis (Kützing) Montagne
• Dasya clavigera (Womersley) Parsons, 1975
• Dasya cliftonii Harvey, 1855
• Dasya coccinea (Hudson) Areschoug, 1845 accepted as Heterosiphonia plumosa (J.Ellis) Batters, 1902
• Dasya coccinea f. tenuis J.Agardh, 1863 accepted as Heterosiphonia plumosa (J.Ellis) Batters, 1902
• Dasya coccinea var. tenuis Liebmann, 1845 accepted as Heterosiphonia plumosa (J.Ellis) Batters, 1902
• Dasya collabens J.D.Hooker & Harvey, 1845
• Dasya collinsiana M.Howe, 1918
• Dasya comata Parsons & Womersley, 1998
• Dasya concinna (J.D.Hooker & Harvey) J.Agardh (uncertain)
• Dasya corallicola Funk, 1927 accepted as Polysiphonia biformis Zanardini, 1860
• Dasya corymbifera J.Agardh, 1841
• Dasya crassa J.Agardh
• Dasya crassipes Harvey, 1855 accepted as Heterosiphonia crassipes (Harvey) Falkenberg, 1901
• Dasya crescens Parsons & Womersley, 1998
• Dasya crinita Parsons & Womersley, 1998
• Dasya crispa Suhr, 1840 accepted as Heterosiphonia crispa (Suhr) Falkenberg, 1901
• Dasya crouaniana J.Agardh, 1890
• Dasya crouanioides Sonder, 1853 accepted as Ptilocladia crouanioides (Sonder) Womersley, 1998
• Dasya cryptica C.W.Schneid., Quach & C.E.Lane, 2017
• Dasya curdieana Harvey, 1863 accepted as Heterosiphonia curdieana (Harvey) Reinbold, 1899
• Dasya cuspidifera Sonder, 1871
• Dasya cylindrica Noda, 1972
• Dasya dalmatica Meneghini
• Dasya decipiens Sonder, 1855 accepted as Dasya naccarioides Harvey, 1844
• Dasya delilei Montagne, 1841 accepted as Asparagopsis taxiformis (Delile) Trevisan de Saint-Léon, 1845
• Dasya dichotomoflabellata P.L.Crouan & H.M.Crouan (uncertain)
• Dasya dictyuroides J.Agardh, 1890 accepted as Wilsonaea dictyuroides (J.Agardh) F.Schmitz, 1893
• Dasya divaricata Zanardini (uncertain)
• Dasya divergens Parsons & Womersley, 1998
• Dasya dubia Suhr, 1840 accepted as Heterosiphonia dubia (Suhr) Falkenberg, 1901
• Dasya eastwoodae Setchell & N.L.Gardner, 1930
• Dasya echigoensis Noda, 1972
• Dasya echinata Stegenga, Bolton & R.J.Anderson, 1997
• Dasya elegans (G.Martens) C.Agardh, 1828 accepted as Dasya baillouviana (S.G.Gmelin) Montagne, 1841 accepted as Dasya pedicellata (C.Agardh) C.Agardh, 1824
• Dasya elegans var. ramosissima Schiffner, 1938 accepted as Dasya baillouviana (S.G.Gmelin) Montagne, 1841 accepted as Dasya pedicellata (C.Agardh) C.Agardh, 1824
• Dasya elongata Noda, 1972
• Dasya elongata Sonder, 1845
• Dasya enomotoi Y.Yamagishi, M.Masuda & T.Abe, 2014
• Dasya extensa Sonder ex Kützing, 1864
• Dasya feredayae Harvey, 1859 accepted as Micropeuce feredayae (Harvey) Kylin ex P.C.Silva, 1996
• Dasya feredayae var. contractior J.Agardh, 1863 accepted as Micropeuce feredayae (Harvey) Kylin ex P.C.Silva, 1996
• Dasya festiva Meneghini
• Dasya flagellifera Børgesen, 1934
• Dasya flocculosa Zanardini, 1858
• Dasya frutescens Harvey, 1855
• Dasya fruticulosa A.H.S.Lucas, 1935
• Dasya gibbesii Harvey, 1853 accepted as Heterosiphonia gibbesii (Harvey) Falkenberg, 1901
• Dasya guernisaci (P.L.Crouan & H.M.Crouan) P.L.Crouan & H.M.Crouan (uncertain)
• Dasya guichensis Reinbold, 1897 accepted as Heterosiphonia wrangelioides (Harvey) Reinbold, 1899
• Dasya gunniana (Harvey) Harvey, 1847 accepted as Heterosiphonia gunniana (Harvey) Reinbold, 1899
• Dasya gunniana f. intermedia J.Agardh, 1863 accepted as Heterosiphonia gunniana (Harvey) Reinbold, 1899
• Dasya gunniana f. lawrenciana (Harvey) J.Agardh, 1863 accepted as Heterosiphonia lawrenciana (Harvey) Parsons, 1975
• Dasya gunniana var. lawrenciana (Harvey) Harvey, 1863 accepted as Heterosiphonia lawrenciana (Harvey) Parsons, 1975
• Dasya haffiae Harvey, 1859
• Dasya haitiana S.Fredericq & J.N.Norris, 1986
• Dasya hapalathrix Harvey, 1859
• Dasya harveyi Ashmead, 1858
• Dasya harveyi Kützing, 1864 accepted as Lophocladia kuetzingii (Kuntze) P.C.Silva, 1996
• Dasya helenae Farlow
• Dasya hirta J.Agardh, 1894 accepted as Doxodasya hirta (J.Agardh) Womersley & Parsonss, 2003
• Dasya hookeri Parsons & Womersley, 1998