Blechnum is a genus of ferns. Two very different circumscriptions of the genus are used by different authors. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Blechnum is one of 18 genera in the subfamily Blechnoideae of the family Blechnaceae, and has about 30 species. Other sources place many more species in the genus, with only two other genera in the subfamily. The genus then has about 250 species.
Species placed in Blechnum by Plants of the World Online, which uses the broad circumscription, but transferred to other genera by the Checklist of Ferns and Lycophytes of the World, which uses the narrow circumscription, are listed below together with their alternative placement.
A Blechnum acanthopodum T.C.Chambers & P.A.Farrant = Parablechnum acanthopodum (T.C.Chambers & P.A.Farrant) Gasper & Salino Blechnum acutum (Desv.) Mett. = Lomaridium acutum (Desv.) Gasper & V.A.O.Dittrich Blechnum aequatoriense A.Rojas = Austroblechnum aequatoriense (A.Rojas) Gasper & V.A.O.Dittrich Blechnum × aggregatum (Colenso) Tindale = Austroblechnum × aggregatum (Colenso) Gasper & V.A.O.Dittrich Blechnum amabile Makino = Struthiopteris amabilis (Makino) Ching Blechnum ambiguum C.Presl = Parablechnum ambiguum (Kaulf. ex C.Presl) C.Presl Blechnum andinum C.Chr. = Austroblechnum andinum (Baker) Gasper & V.A.O.Dittrich Blechnum articulatum (F.Muell.) S.B.Andrews = Parablechnum articulatum (F.Muell.) Gasper & Salino Blechnum ascendens A.Rojas = Austroblechnum ascendens (A.Rojas) Gasper & V.A.O.Dittrich Blechnum asperum (Klotzsch) J.W.Sturm = Austroblechnum asperum (Klotzsch) Gasper & V.A.O.Dittrich Blechnum atropurpureum A.R.Sm. = Parablechnum atropurpureum (A.R.Sm.) Gasper & Salino Blechnum attenuatum (Sw.) Mett. = Lomaridium attenuatum (Sw.) Gasper & V.A.O.Dittrich Blechnum auratum (Fée) R.M.Tryon & Stolze = Lomariocycas aurata (Fée) Gasper & A.R.Sm. Blechnum austrocaledonicum Christenh. = Doodia gracilis Copel.
B Blechnum bakeri C.Chr. = Cranfillia bakeri (C.Chr.) Vázquez Ferreira & Molino S. Blechnum banksii (Hook.f.) Mett. = Austroblechnum banksii (Hook. fil.) Gasper & V.A.O.Dittrich Blechnum bicolor M.Kessler & A.R.Sm. = Parablechnum bicolor (M.Kessler & A.R.Sm.) Gasper & Salino Blechnum biforme (Baker) Christ = Lomaridium biforme (Baker) Gasper & V.A.O.Dittrich Blechnum binervatum (Poir.) C.V.Morton & Lellinger = Lomaridium binervatum (Poir.) Gasper & V.A.O.Dittrich Blechnum binerve (Hook.) C.Chr. = Lomaridium xiphophyllum (Baker) Gasper & V.A.O.Dittrich Blechnum bolivianum M.Kessler & A.R.Sm. = Parablechnum bolivianum (M.Kessler & A.R.Sm.) Gasper & Salino Blechnum bonapartei Rakotondr. = Lomaridium bonapartei (Rakotondr.) Gasper & V.A.O.Dittrich Blechnum brackenridgei (Carruth.) Perrie & Brownsey = Doodia brackenridgei Carruth. Blechnum brasiliense Desv. = Neoblechnum brasiliense (Desv.) Gasper & V.A.O.Dittrich Blechnum bruneum M.Kessler & A.R.Sm. = Lomaria brunea (M.Kessler & A.R.Sm.) Gasper & V.A.O.Dittrich
C Blechnum camfieldii Tindale = Parablechnum camfieldii (Tindale) Gasper & Salino Blechnum capense Burm.f. = Parablechnum capense (Burm. fil.) Gasper & Salino Blechnum cartilagineum Sw. = Oceaniopteris cartilaginea (Sw.) Gasper & Salino Blechnum castaneum (Makino) Makino & Nemoto = Struthiopteris castanea (Makino) Nakai Blechnum chambersii Tindale = Austroblechnum lanceolatum (R.Br.) Gasper & V.A.O.Dittrich Blechnum chauliodontum Copel. = Parablechnum chauliodontum (Copel.) Gasper & Salino Blechnum chiriquanum (Broadh.) C.Chr. = Parablechnum chiriquanum (Broadh.) Gasper & Salino Blechnum christii C.Chr. = Parablechnum christii (C.Chr.) Gasper & Salino Blechnum cochabambense M.Kessler & A.R.Sm. = Parablechnum cochabambense (M.Kessler & A.R.Sm.) Gasper & Salino Blechnum colensoi (Hook.f.) N.A.Wakef. = Austroblechnum colensoi (Hook. fil.) Gasper & V.A.O.Dittrich Blechnum columbiense Hieron. = Lomariocycas columbiensis (Hieron.) Gasper & A.R.Sm. Blechnum confusum (Fourn.) Brownlie = Parablechnum confusum (E.Fourn.) Gasper & Salino Blechnum contiguum Mett. = Lomaridium contiguum (Mett.) Gasper & V.A.O.Dittrich Blechnum corbassonii Brownlie = Parablechnum corbassonii (Brownlie) Gasper & Salino Blechnum cordatum (Desv.) Hieron. = Parablechnum cordatum (Desv.) Gasper & Salino Blechnum corralense Espinosa = Austroblechnum corralense (Espinosa) Gasper & V.A.O.Dittrich Blechnum cyatheoides (Kaulf.) Christenh. = Sadleria cyatheoides Kaulf. Blechnum cycadifolium (Colla) J.W.Sturm = Lomariocycas cycadifolia (Colla) Gasper & A.R.Sm.
D Blechnum decrescens Rakotondr. = Lomariocycas decrescens (Rakotondr.) Gasper & A.R.Sm. Blechnum dendrophilum (Sodiro) C.Chr. = Lomaridium dendrophilum (Sodiro) Gasper & V.A.O.Dittrich Blechnum deplanchei (Baker) C.Chr. = Cranfillia deplanchei (Baker) Vázquez Ferreira & Gabriel y Galán Blechnum difforme Copel. = Austroblechnum difforme (Copel.) Gasper & V.A.O.Dittrich Blechnum dilatatum (Brause) T.C.Chambers & P.A.Farrant = Parablechnum dilatatum (T.C.Chambers & P.A.Farrant) Gasper & Salino Blechnum discolor (Forst.) Keyserl. = Lomaria discolor (G.Forst.) Willd. Blechnum dissectum (Parris) Christenh. = Doodia dissecta Parris Blechnum divergens (Kunze) Mett. = Austroblechnum divergens (Kunze) Gasper & V.A.O.Dittrich Blechnum diversifolium Mett. = Diploblechnum diversifolium (Mett.) Gasper & V.A.O.Dittrich Blechnum dives (Kunze) Christenh. = Doodia dives Kunze Blechnum doodianum Christenh. = Doodia heterophylla (F.M.Bailey) Domin Blechnum durum (T.Moore) C.Chr. = Austroblechnum durum (T.Moore) Gasper & V.A.O.Dittrich
E–F Blechnum eburneum Christ = Cleistoblechnum eburneum (Christ) Gasper & Salino Blechnum egregium Copel. = Oceaniopteris egregia (Copel.) Gasper & Salino Blechnum ensiforme (Liebm.) C.Chr. = Lomaridium ensiforme (Liebm.) Gasper & V.A.O.Dittrich Blechnum falciforme (Liebm.) C.Chr. = Parablechnum falciforme (Liebm.) Gasper & Salino Blechnum fernandezianum (Looser) Prada & Rolleri = Austroblechnum fernandezianum (Looser) Gasper & V.A.O.Dittrich Blechnum filiforme (A.Cunn.) Ettingsh. = Icarus filiformis (A.Cunn.) Gasper & Salino Blechnum finlaysonianum Wall. ex Hook. & Grev. = Blechnopsis finlaysoniana (Wall. ex Hook. & Grev.) C.Presl Blechnum floresii C.Chr. = Austroblechnum divergens (Kunze) Gasper & V.A.O.Dittrich Blechnum fluviatile (R.Br.) Lowe = Cranfillia fluviatilis (R.Br.) Gasper & V.A.O.Dittrich Blechnum fragile (Liebm.) C.V.Morton & Lellinger = Lomaridium fragile (Liebm.) Gasper & V.A.O.Dittrich Blechnum francii Rosenst. = Oceaniopteris francii (Rosenst.) Gasper & Salino Blechnum fraseri (A.Cunn.) Luerss. = Diploblechnum fraseri (A.Cunn.) De Vol Blechnum fullagari (F.Muell.) C.Chr. = Cranfillia fullagari (T.C.Chambers & P.A.Farrant) Gasper & V.A.O.Dittrich Blechnum fuscosquamosum A.Rojas = Lomaridium fuscosquamosum (A.Rojas) Gasper & V.A.O.Dittrich
G Blechnum gemmascens Alston = Parablechnum gemmascens (Alston) Gasper & Salino Blechnum geniculatum T.C.Chambers & P.A.Farrant = Cranfillia geniculata (T.C.Chambers & P.A.Farrant) Gasper & V.A.O.Dittrich Blechnum ghiesbreghtii (Baker) C.Chr. = Austroblechnum stoloniferum (Mett. ex E.Fourn.) Gasper & V.A.O.Dittrich Blechnum gibbum (Labill.) Mett. = Oceaniopteris gibba (Labill.) Gasper & Salino Blechnum glabrescens T.C.Chambers & Sykes = Cranfillia glabrescens (T.C.Chambers & Sykes) Gasper & V.A.O.Dittrich Blechnum glaziovii (Christ) Rolleri & Prada = Parablechnum glaziovii (Christ) Gasper & Salino Blechnum gregsonii (Watts) Tindale = Parablechnum gregsonii (Tindale) Gasper & Salino
H Blechnum hancockii Hance = Struthiopteris hancockii (Hance) Tagawa Blechnum hieronymi Brause = Parablechnum hieronymi (Brause) Gasper & Salino Blechnum hindii (Tindale ex T.C.Chambers) Christenh. = Doodia hindii Tindale ex T.C.Chambers Blechnum hirsutum Rosenst. = Cranfillia hirsuta (Rosenst.) Gasper & V.A.O.Dittrich Blechnum howeanum T.C.Chambers & P.A.Farrant = Parablechnum howeanum (T.C.Chambers & P.A.Farrant) Gasper & Salino Blechnum humbertii Tardieu = Parablechnum marginatum (Fée) Gasper & Salino var. humbertii (Tardieu) Gasper & Salino
I–K Blechnum inflexum (Kunze) Kuhn = Lomaria inflexa Kunze Blechnum insigne (Hook.) C.M.Kuo = Brainea insignis (Hook.) J.Sm. Blechnum integrifrons Bonap. ex Rakotondr. = Austroblechnum integrifrons (Bonap. ex Rakotondr.) Gasper & V.A.O.Dittrich Blechnum jamaicense C.Chr. = Austroblechnum jamaicense (Broadh.) Gasper & V.A.O.Dittrich Blechnum keysseri Rosenst. = Austroblechnum keysseri (Rosenst.) Gasper & V.A.O.Dittrich Blechnum kunthianum C. Chr. = Lomaridium angustifolium (Kunth.) Vicent & Gabriel y Galán
L Blechnum lechleri Mett. = Austroblechnum lechleri (T.Moore) Gasper & V.A.O.Dittrich Blechnum lehmannii Hieron. = Austroblechnum lehmannii (Hieron.) Gasper & V.A.O.Dittrich Blechnum lenormandii (Baker) Diels = Diploblechnum lenormandii (Baker) Gasper & V.A.O.Dittrich Blechnum leyboldtianum C.Chr. = Austroblechnum leyboldtianum (Phil.) Gasper & V.A.O.Dittrich Blechnum lherminieri (Bory) Mett. = Austroblechnum lherminieri (Bory) Gasper & V.A.O.Dittrich Blechnum lima Rosenst. = Parablechnum lima (Rosenst.) Gasper & Salino Blechnum lineare (C.Moore & J.Sm.) Christenh. = Doodia linearis C.Moore ex J.Sm. Blechnum lineatum (Sw.) Hieron. = Parablechnum lineatum (Sw.) Gasper & Salino Blechnum longepetiolatum Tardieu = Lomariocycas longepetiolata (Tardieu) Gasper & A.R.Sm. Blechnum longicauda C.Chr. = Cranfillia longicauda (C.Chr.) Gasper & V.A.O.Dittrich Blechnum longipinna Rakotondr. = Lomariocycas longipinna (Rakotondr.) Gasper & A.R.Sm. Blechnum longistipitatum A.Rojas = Parablechnum longistipitatum (A.Rojas) comb. ined. Blechnum loxense (Kunth) Hook. ex Salomon = Parablechnum loxense (Kunth) Gasper & Salino Blechnum lyonii (O.Deg.) Christenh. = Doodia lyonii O.Deg.
M Blechnum madagascariense Tardieu = Lomariocycas madagascariensis (Tardieu) Gasper & A.R.Sm. Blechnum magellanicum (Desv.) Mett. = Lomariocycas magellanica (Desv.) Gasper & A.R.Sm. Blechnum marginatum Kuhn = Parablechnum marginatum (Fée) Gasper & Salino Blechnum marquesense (E.D.Br.) Christenh. = Doodia marquesensis E.D.Br. Blechnum maximum (R.Br. ex C.Chr.) Christenh. = Doodia maxima (R.Br.) J.Sm. Blechnum maxonii C.Chr. = Austroblechnum lehmannii (Hieron.) Gasper & V.A.O.Dittrich Blechnum medium (R.Br.) Christenh. = Doodia media R.Br. Blechnum melanocaulon (Brack.) T.C.Chambers & P.A.Farrant = Austroblechnum melanocaulon (Brack.) Gasper & V.A.O.Dittrich Blechnum melanopus Hook. = Blechnidium melanopus (Hook.) T.Moore Blechnum membranaceum (Colenso) Mett. = Austroblechnum membranaceum (Colenso ex Hook.) Gasper & V.A.O.Dittrich Blechnum microphyllum (Goldm.) C.V.Morton = Austroblechnum microphyllum (Goldm.) Gasper & V.A.O.Dittrich Blechnum milnei (Carruth.) C.Chr. = Parablechnum milnei (Carruth.) Gasper & Salino Blechnum minus (R.Br.) Ettingsh. = Parablechnum minus (R.Br.) Gasper & Salino Blechnum mochaenum G.Kunkel = Austroblechnum lechleri (T.Moore) Gasper & V.A.O.Dittrich Blechnum molle (Parris) Christenh. = Doodia mollis Parris Blechnum monomorphum R.C.Moran & B.Øllg. = Parablechnum monomorphum (R.C.Moran & B. Øllg.) Gasper & Salino Blechnum montanum T.C.Chambers & P.A.Farrant = Parablechnum montanum (T.C.Chambers & P.A.Farrant) Gasper & Salino Blechnum moorei C.Chr. = Oceaniopteris ciliata (T.Moore) Gasper & Salino Blechnum moranianum A.Rojas = Parablechnum moranianum (A.Rojas) Gasper & Salino Blechnum moritzianum (Klotzsch) Hieron. = Lomariocycas moritziana (Klotzsch) Gabriel y Galán & Vicent
N Blechnum neglectum (F.M.Bailey) R.K.Wilson & Bayly = Diploblechnum neglectum (F.M.Bailey) Gasper & V.A.O.Dittrich Blechnum neohollandicum Christenh. = Doodia aspera R.Br. Blechnum nesophilum T.C.Chambers & P.A.Farrant = Parablechnum nesophilum (T.C.Chambers & P.A.Farrant) Gasper & Salino Blechnum nigrocostatum A.Rojas = Lomaridium nigrocostatum (A.Rojas) Gasper & V.A.O.Dittrich Blechnum nigrum (Colenso) Mett. = Cranfillia nigra (Colenso) Gasper & V.A.O.Dittrich