Many Genera of living Diatoms are known, with an estimated 100000 extant species! Here is the very long Genus list, that includes both recent and fossil species:
Abas Acanthoceras Acanthodiscus Achnantella Achnantheiopsis Achnanthepyla Achnanthes Achnanthidium Achnanthosigma Acigonium Actinella Actiniscus Actinoclava Actinocyclus Actinodictyon Actinodiscus Actinogonium Actinogramma Actinoneis Actinophaenia Actinoptychus Actinostephanos Adlafia Adoneis Afrocymbella Agardhia Aggericorona Ailuretta Alloioneis Allonitzschia Altana Alveoflexus Alveolophora Alveovallum Alveus Ambistria Amblypyrgus Amicula Amphicampa Amphicocconeis Amphidiscus Amphipentas Amphipleura Amphiprora Amphiraphia Amphitetras Amphitrite Amphitropis Amphora Amphoropsis Amphorotia Anaulus Ancoropsis Ancylopyrgus Andrewsiella Aneumastus Angulopyxidium Anisodiscus Annellus Annularius Anomoeoneis Anorthoneis Antelminellia Anthemodiscus Anthodiscina Anthodiscus Anuloplicata Aporodiscus Apterosoma Arachnodiscus Arachnoidiscus Araniscus Archaegladiopsis Archaelepidodiscus Archeopantocsekia Archepyrgus Archibaldia Arcocellulus Arcus Ardissonea Argonauta Aristella Arthrodesmus Arthrogyra Arthrotoma Astartiella Asterionella Asterionellopsis Asteroactina Asterodiscus Asterolampra Asteromphalus Asteroplanus Astrosyne Attheya Aulacocystis Aulacodiscus Aulacoseira Auliscus Auricula Auriculopsis Austariella Australodiscus Azpeitia Azpeitiopsis
Bacillaria Bacteriastrum Bacterosira Bactryllium Baculites Baileya Balanosa Bangia Banquisia Basilicostephanus Baxteria Baxteriopsis Bellerochea Belonastrum Belonidium Benetorus Bennettella Bergonia Berkeleya Berkella Biblarium Bicornis Bicudoa Biddulphia Biddulphiopsis Bifibulatia Bilingua Bipalla Biremis Biturricula Bleakeleya Blochia Bogorovia Bolewskia Bonea Botellus Brachybaculites Brachysira Brandinia Brasiliella Brassierea Brebissonia Brevilinea Brevisira Briggera Brightwellia Brockmanniella Brunia Bruniella Bruniopsis Buryatia
Calcothrix Callimastogloia Calodiscus Caloneis Calyptosporium Calyptrella Campylodiscus Campyloneis Campylopyxis Campylosira Campylostylus Candollella Capartogramma Caponea Capsula Carrodoria Castracania Catacombas Catenula Catillus Cavernosa Cavinula Cavitatus Centrodiscus Centronella Centroporus Ceramium Ceratangula Cerataulina Cerataulus Ceratodiscus Ceratoneis Ceratophora Cestodiscus Chaetoceros Chamaepinnularia Chaos Charcotia Chasea Cheloniodiscus Chrysanthemodiscus Chuniella Cistula Cladogramma Cladomphalus Clavicula Clavularia Clevamphora Cleveia Clevia Climacidium Climacodium Climaconeis Climacosira Climacosphenia Clipeoparvus Cocconeiopsis Cocconeis Cocconema Coenobiodiscus Cohniella Colletonema Colliculoamphora Collumicylindrus Cometes Compositus Concentrodiscus Conferva Conticribra Corbellia Corethron Corinna Corona Coronia Coronodiscus Cortinocornus Coscineis Coscinodiscopsis Coscinodiscus Coscinodon Coscinophaena Coscinorima Coscinosira Cosmiodiscus Cosmioneis Costopyxis Cotyledon Coxia Craspedodiscus Craspedopleura Craspedoporus Craspedostauros Crateriportula Craticula Creania Cresswellia Creswellia Cribrionella Cristodiscus Crossophialus Crucicostulifera Crucidenticula Crystalia Ctenophora Cuneolus Cussia Cycloites Cyclophora Cycloplea Cyclosira Cyclostephanopsis Cyclostephanos Cyclotella Cyclotubicoalitus Cylindropyxis Cylindrospira Cylindrotheca Cymatodiscus Cymatogonia Cymatoneis Cymatonitzschia Cymatopleura Cymatosira Cymatotheca Cymbamphora Cymbella Cymbellafalsa Cymbellonitzschia Cymbellopsis Cymbophora Cymbopleura Cymbosira Cypellachaetes Cystopleura
Dactylacanthis Dactyliosolen Dalai-lama Dasyangea Debya Decussata Delicata Delphineis Dendrella Dendrogonia Denticella Denticula Denticulopsis Desikaneis Desmidium Desmogonium Detonia Detonula Dextradonator Diadema Diademoides Diadesmis Diatoma Diatomella Diatomosira Dichomenis Dichotropiscus Dickensoniaforma Dickieia Dicladia Dicladiopsis Dictyocha Dictyolampra Dictyoneis Dictyopyxis Didymohelix Didymosphenia Dimeractis Dimeregramma Dimeregrammopsis Dimidiata Diommatetras Diomphala Diplomenora Diploneis Diprora Disciferium Discodiscus Discoites Disconeis Discoplea Discosira Discostella Discus Disiphonia Dispinodiscus Distephanosira Distichanthes Distrionella Ditylum Donkinia Doryphora Dossetia Drepanotheca Drewsandria Druridgia Dunia Dycladia
Echinella Echinodiscus Echinopysis Echinopyxis Ectodictyon Ehrenbergia Ehrenbergiulva Ellerbeckia Emersonia Encyonema Encyonopsis Endictya Endosigma Endostauron Entogonia Entomogaster Entomoneis Entopyl Envekadea Eolimna Eoseira Ephemera Epipellis Epiphalaina Epithelion Epithemia Ethmodiscus Eucampia Euceratoneis Eucocconeis Eumeridion Eunophora Eunotia Eunotioforma Eunotiopsis Eunotogramma Euodia Euodiella Euphyllodium Eupleuria Eupodiscus Eupterotrum Eurossia Eustephanias Excentron Exilaria Extubocellulus
Falcatella Falcula Fallacia Fenestrella Fibula Fistulifera Flexibiddulphia Florella Fogedia Fontigonium Fossula Fovirhombus Fragilaria Fragilariella Fragilariforma Fragilariopsis Frankophila Frickea Frustulia Fryxelliella Fusiformella Fusotheca
Gaillonella Geissleria Gemellodiscus Genkalia Gephyria Germainiella Giffenia Girodella Gladiopsis Gladius Gleseria Gloeodictyon Gloeonema Gloionema Glorioptychus Glyphodesmis Glyphodiscus Golovenkinia Gomphocaloneis Gomphocymbella Gomphocymbellopsis Gomphogramma Gomphoneis Gomphonella Gomphonema Gomphonemopsis Gomphonitzschia Gomphopleura Gomphoseptatum Gomphosphenia Gomphotheca Gonioceros Goniothecium Gossleria Gossleriella Grammatonema Grammatophora Grammonema Grayia Groentvedia Grovea Grunovia Grunoviella Grunovwiella Grunowia Guinardia Gutwinskiella Gyrocylindrus Gyrodiscus Gyropandorus Gyroptychus Gyrosigma
Halamphora Halionyx Halurina Hamatusia Handmannia Hannaea Hantzschia Hantzschiopsidea HasleaHaynaldella Haynaldia Heibergia Helicotheca Heliopelta Helisella Helminthopsidella Helminthopsis Hemiaulus Hemidiscus Hemiptychus Hemizoster Hendeya Henseniella Henshawia Hercotheca Heribaudia Hesslandia Heterangion Heterocampa Heterodictyon Heteromphala Heteroneis Heterostephania Himantidium Himantosoma Hippodonta Homalodiscus Homoeocladia Hormophora Horodiscus Horstia Humidophila Hustedtia Hustedtiella Huttonia Huttoniella Hyalinella Hyalodictya Hyalodiscopsis Hyalodiscus Hyaloneis Hyalopoda Hyalopyxis Hyalosigma Hyalosira Hyalosynedra Hyalotrochus Hydrolinum Hydrosera Hydrosilicon Hydrosirella Hygropetra Hyperion
Iconella Ikebea Imparvalvia Incisoria Inoderma Insilella Isodiscus Isthmia Isthmiella
Janischia Jousea
Kannoa Karayevia Katahiraia Kentrodiscus Keratophora Kerkis Khursevichia Kidoa Kisseleviella Kittonia Klinodiscus Kobayasia Kobayasiella Koernerella Koizumia Kolbesia Kolpoda Kozhowia Kozloviella Krasskella Kreagra Krsticiella Ktenodiscus Kuemmerlea Kurpiszia
Labellicula Lacunicula Lacustriella Lamella Lampriscus Lamprotediscus Lancineis Lauderia Lauderiopsis Lecohuia Lemnicola Lennoxia Lentiliforma Lepidodiscus Leptocylindrus Leptoscaphos Leudugeria Leyanella Libellus Licmophora Licmosoma Licmosphenia Ligulatium Lindavia Lioloma Lioneis Liostephania Liparogyra Liradiscus Liriogramma Lisitzinia Lithobotrys Lithocampe Lithodesmioides Lithodesmium Lithostylidium Livingstonia Lobarzewskya Lobodiscus Lomonycus Longinata Lophotheca Lunella Lunularia Lunulina Luticola Lyngbyea Lyrella Lysicyclia Lysigonium
Macrora Maluina Mammidion Mammula Manguinea Mannsia Margaritoxon Margaritum Martyana Mastodiscus Mastogloia Mastogonia Mastoneis Mayamaea Mediaria Mediopyxis Medlinia Melchersiela Melonavicula Melosira Membraneis Meretrosulus Meridion Meristosolen Mesasterias Mesocena Mesodictyon Mesodictyopsis Meuniera Michelcostea Micrampulla Microcostatus Microfissurata Micromega Microneis Microorbis Micropodiscus Microsiphona Microsolenia Microspodiscus Microstigma Microtabella Microtheca Minidiscus Minutocellus Miosira Miraltia Mitralifer Moelleria Moisseevia Monema Monile Monobrachia Monoceros Monocladia Monogramma Mononeis Monopsia Monopsis Moreneis Muelleria Muelleriella Muelleriopsis Mycetacanthus Myxobaktron
Nagumoea Nanofrustulum Nanoneis Naunema Navicella Navicula Naviculadicta Naviculopsis Navicymbula Navigiolum Neidiomorpha Neidiopsis Neidium Nematoplata Neobrunia Neocalyptrella Neodelphineis Neodenticula Neodetonia Neodiatoma Neofragilaria Neograya Neohuttonia Neostreptotheca Neosynedra Nephrodiscus Nephroneis Nikolaevia Nitzschia Nitzschiella Nitzschiopsidea Noszkya Nothoceratium Novilla Nupela
Ochigma Ocularia Odontella Odontella-lampriscus Odontidium Odontodiscus Odontotropis Oestrupia Okedenia Olifantiella Omphalopelta Omphalophortron Omphalopsis Omphalotheca Oncobyrsa Oncodiscus Oncosphenia Opephora Opephoropsis Ophidocampa Oricymba Orthoneis Orthoseira Orthosira Orthosoma Orthotropis Oscillatoria Oshitea Oxyamphora Oxyneis
Pachyneis Palaeotrigonium Paleopandorus Palmella Palmeria Palmerina Pantocsekia Papiliocellulus Pappia Paradesmus Paralia Paralya Paraplaconeis Parelion Parlibellus Parodontella Parthaea Pauliella Pelagodictyon Pentapodiscus Peponia Peragallia Peragalloella Perideraion Perinotia Periptera Peripteropsis Perissonoe Peristephania Perithyra Perizonium Peronia Peroniopsis Perrya Petitia Petrochiscus Petrodictyon Petroneis Phacodiscus Phaeodactylum Pharyngoglossa Phlyctaenia Pierrecomperia Pinnuavis Pinnulaira Pinnularia Pinnulariosigma Pinnunavis Placoneis Plagiodiscus Plagiogramma Plagiogrammopsis Plagiolemma Plagiotropis Planktoniella Planothidium Platessa Playaensis Plegmolobos Pleurocyclos Pleurodesmium Pleurodiscina Pleurodiscus Pleuroneis Pleurosigma Pleurosiphonia Pleurosira Pleurostauron Pleurostaurum Pleurozonaria Pliocaenicus Ploiaria Plumosigma Plurifenestra Podiscus Podocystis Pododiscus Podosira Podosphenia Pogoneis Poloniasira Polygonalium Polymyxus Pomphodiscus Ponticella Pontodiscus Porannulus Poretzkia Porguenia Porocyclia Porodiscus Porosira Porostauros Porosularia Porotheca Porpeia Potamodiscus Praecymatosira Praeepithemia Praeparalia Praethalassiosiropsis Praetriceratium Pravifusus Prestauroneis Pritchardia Proboscia Proboscidea Proboscineis Progonia Progonoia Prorocentrum Prorostauros Proschkinia Proteucylindrus Protokeelia Protoraphis Protorhaphoneis Psammococconeis Psammodictyon Psammodiscus Psammogramma Psammoneis Psammosynedra Psammothidium Pseudauliscus Pseudencyonema Pseudo-eunotia Pseudo-nitzschia Pseudoamphiprora Pseudoaulacodiscus Pseudoaulacosira Pseudoauliscus Pseudocerataulus Pseudocoscinodiscus Pseudodictyoneis Pseudodimerogramma Pseudodiploneis Pseudofallacia Pseudogomphonema Pseudoguinardia Pseudohimantidium Pseudohyalodiscus Pseudoleyanella Pseudomastogloia Pseudonitzschia Pseudoperonia Pseudopodosira Pseudopyxilla Pseudorutilaria Pseudosolenia Pseudostaurosira Pseudostaurosiropsis Pseudostephanodiscus Pseudostictodiscus Pseudostriatella Pseudosynedra Pseudotriceratium Pteroncola Pterotheca Ptychodiscus Pulchella Punctastriata Punctatriata Puncticulata Pyrgodiscus Pyrgupyxis Pyxidicula Pyxilla
Quadrodiscus
Radialiplicata Radiodiscus Radiopalma Ralfsia Rancia Raphidivergens Raphidodiscus Raphidogloia Raphoneis Rattrayella Reicheltia Reimeria Reimerothrix Rexlowea Rhabdium Rhabdonema Rhabdosira Rhapalodia Rhaphidogloea Rhaphidophora Rhaphiophorasphaera Rhaphoneis Rhiphidophora Rhipidophora Rhizonotia Rhizosolenia Rhoiconeis Rhoicosigma Rhoicosphaenia Rhoicosphenia Rhoikoneis Rhoikosigma Rhopalodia Rhynchopyxis Richelia Riedelia Rimoneis Robinsetta Rocella Roperia Rosaria Rossia Rossiella Rossithidium Roundia Rouxia Rouxiopis Rouxiopsis Rutilaria Rutilariopsis Rylandsia
Sagittula Salacia Sameioneis Sarcophagodes Sawamuraia Scalprum Scalptrum Scapha Sceletonema Sceptroneis Sceptronema Schimperiella Schizonema Schizostauron Schmidtia Schmidtiella Schroederella Schuettia Schulziella Scoliodiscus Scolioneis Scoliopleura Scoliotropis Scoresbya Scytonema Scyzonema Secallia Sellaphora Seminavis Semiorbis Semseyia Sextiputeus Sheshukova Sheshukovia Shionodiscus Sichuania Sieminskia Sigma Sigmatella Simonsenia Simonseniella Siphonodiscus Skeletomastus Skeletonema Skeletonemopsis Skvortzowia Smithiella Solium Spatangidium Spermatogonia Sphaerophora Sphaerotermia Sphenella Sphenoneis Sphenosira Sphinctocystis Sphynctolethus Spicaticribra Spinigera Spinivinculum Spinodiscus Spinosira Spirodiscus Spongia Spongophyllium Spumorbis Stauroforma Staurogramma Stauroneis Stauronella Staurophora Stauropsis Stauroptera Staurosigma Staurosira Staurosirella Staurotropis Stelladiscus Stellarima Stelodiscus Stenoneis Stenopterobia Stephanocostis Stephanocyclus Stephanodiscus Stephanogonia Stephanonycites Stephanopyxis Stephanosira Stictocyclus Stictodesmis Stictodiscus Stictolecanon Stigmaphora Stigmophora Stilus Stoermeria Stoschia Stoschiella Strangulonema Strelnikovia Streptommion Streptotheca Striatella Strictolecanon Sturtiella Stylaria Styllaria Stylobiblium Stylorium Subsilicea Suriraya Surirella Symbelpharis Symbolophora Syncyclia Syndendrium Syndera Syndetocystis Syndetoneis Synedra Synedrella Synedropsis Synedrosphaenia Synedrosphenia Syringidium Syrinx Systephania Szechenyia
Tabellaria Tabularia Tabulariopsis Tabulina Takanoa Talaroneis Temachium Temperea Terebraria Terpsinoe Tertiariopsis Tertiarius Tessella Tetrachaeta Tetracyclus Tetragramma Tetralophus Tetramphora Tetrapodiscus Tetraspila Thalassiocyclus Thalassioneis Thalassionema Thalassiophysa Thalassiosira Thalassiosiropsis Thalassiothrix Thamnodiscus Thaumaleorhabdium Thaumatonema Thumia Tibiella
Tortilaria Toxarium Toxonidea Toxosira Trachyneis Trachysphenia Triaulacias Tribrachia Triceras Triceratium Trichotoxon Trigonium Trinacria Tripodiscus Tripterion Trisystema Trochiscia Trochosira Trochosirella Trochosiropsis Trochus Tropidoneis Tropidosiphonus Trossulus Truania Truncatulus Tryblionella Tryblioptychus Tschestnovia Tubaformis Tubularia Tubulariella Tumulopsis Tursiocola
Ulnaria Ulva Undatella Undatodiscus Unguiella Upothema Urosolenia
Valdiviella Vallodiscus Vanheurckella Vanheurckia Vanhoeffenus Vavia Veigaludwigia Veniaminia Vernadskowia Vesiculifera Vibrio Vikingea Vorticella Vulcanella
Weissflogia Willemoesia Wittia
Xanthiopsis Xanthiopyxis Xystotheca
Yoshidaia
Zotheca Zygoceros
The word Diatoms in various languages: diatome (Afrikaans), diatomeve (Albanian), الدياتومات (Arab), дыатамавая водарасцяў (Belarusian), rozsivky (Czech), 硅藻 (Chinese), 규조류 (Korean), kiselalger (Danish), Danmhairgis (Gaeilge), piilevät (Finnish), diatomées (French), 珪藻 (Japanese), διατόμων (Greek), Diatomee (Italian), kiselalger (Norwegian), okrzemki (Polish), diatomáceas (Portoguese), диатомовые водоросли (Russian), diatomeas (Spanish), kiselalger (Swedish), Kieselalgen (German), діатомові водорості (Ukrainian), kovamoszat (Hungarian)