Spirogyra je rod parožina iz porodice Conjugatophyceae (Zygnemataceae). Sastavljen je od oko 400 vrsta, koje žive u slatkim vodama, stvarajući velike zelene mase.
Izgled Spirogyra je nitasta alga široka 10-100 mikrometara, dok duljina može iznositi i nekoliko centimetara. Stanična stijenka ima dva sloja. Vanjski je sloj sastavljen od pektina, koji se otapa u vodi i čini algu sluzavom na dodir. Unutarnji je izgrađen od celuloze. Kloroplastima broj varira, te se nalaze na rubovima citoplazme. Spiralnog su oblika, pa tako i algi daju oblik. Svaki kloroplast sadrži nekoliko pirenoida, koji su središta za proizvodnju škroba fotosintezom.
Razmnožavanje Spirogyra se može razmnožavati spolno i rijetko nespolno. Kod nespolnog iz samo jednog dijela uzastopnim mitozama nastaje nova alga. Spolni način razmnožavanja je konjugacija.
Konjugacija Dvije niti spirogire oblikuju konjugacijske cijevi. Sadržaj jedne stanice prolazi kroz cijev i spaja se sa stanicom druge niti, te tako nastaje zigospora, koja može preživjeti i u vrlo teškim uvjetima. Nakon nekog vremena počinju rasti nove niti. Vrste
Spirogyra abbreviata Zheng Spirogyra acanthophora (Skuja) Czurda Spirogyra acumbentis Vodenicarov Spirogyra adjerensis Gauthier-Lièvre Spirogyra adnata (Vaucher) Kützing Spirogyra adornata Ling Spirogyra aequalis F.L.Harvey Spirogyra aequinoctialis G.S.West Spirogyra affinis (Hassall) Petit Spirogyra africana (F.E.Fritsch) Czurda Spirogyra ahmedabadensis N.D.Kamat Spirogyra alkaliensis Noda Spirogyra alpina Kützing Spirogyra alternata Kützing Spirogyra amphimorpha A.K.M.N.Islam Spirogyra ampilii Ushadevi & Panikkar Spirogyra amplectens Skuja Spirogyra ampliata L.Liu Spirogyra anchora Skuja Spirogyra angolensis Welwitsch Spirogyra angulata Nipkow Spirogyra anjanii Ushadevi & Panikkar Spirogyra anomala Bhashyakarla Rao Spirogyra anzygoapora Singh Spirogyra aphanosculpta Skuja Spirogyra aplanospora Randhawa Spirogyra archanii Ushadevi & Panikkar Spirogyra arcta (C.Agardh) Endlicher Spirogyra arcuata Liu Spirogyra areolata Lagerheim Spirogyra arizonensis Rickert & Hoshaw Spirogyra arthuri Woodhead & Tweed Spirogyra articulata Transeau Spirogyra asiatica Czurda Spirogyra atasiana Czurda Spirogyra atrobrunnea Gauthier-Lièvre Spirogyra aubvillei Gauthier-Lièvre Spirogyra australica Czurda Spirogyra australiensis Möbius Spirogyra austriaca Czurda Spirogyra azygospora R.N.Singh Spirogyra baileyi Schmidle Spirogyra bardhamanensis Kargupta et al. Spirogyra batekiana Gauthier-Lièvre Spirogyra bellis (Hassall) P.Crouan & H.Crouan Spirogyra bengalensis Kargupta & P.Sarma Spirogyra bicalyptrata Czurda Spirogyra bichromatophora (Randhawa) Transeau Spirogyra biformis C.-C.Jao Spirogyra biharensis A.M.Verma & B.Kumari Spirogyra bii Kadlubowska Spirogyra bireticulata Liu Spirogyra borealis Zheng & Ling Spirogyra borgeana Transeau Spirogyra borgei Kadlubowska Spirogyra borkuense Gauthier-Lièvre Spirogyra borysthenica Kasanowsky & Smirnoff [Smirnov] Spirogyra bourrellyana Gauthier-Lièvre Spirogyra braziliensis (Nordstedt) Transeau Spirogyra britannica Godward Spirogyra brunnea Czurda Spirogyra buchetii Petit Spirogyra bullata C.-C.Jao Spirogyra calcarea Transeau Spirogyra calchaquiesiae B.Tracanna Spirogyra californica Stancheva, J.D.Hall, McCourt & Sheath Spirogyra calospora Cleve Spirogyra canaliculata Segar Spirogyra cardinia S.H.Lewis Spirogyra caroliniana G.E.Dillard Spirogyra castanacea G.C.Couch Spirogyra cataeniformis (Hassall) Kützing Spirogyra cavata Vodenicarov Spirogyra chaibasaensis A.K.Mahato Spirogyra chakiaensis (Bhashyakarla Rao) Willi Krieger Spirogyra chandrae Kargupta & R.N.Jha Spirogyra chavarensis Ushadevi & Panikkar Spirogyra chekiangensis C.-C.Jao Spirogyra chenii C.-C.Jao Spirogyra chittagongenensis A.K.M.N.Islam Spirogyra chungkingensis C.-C.Jao Spirogyra chuniae C.-C.Jao Spirogyra circumvarians Kargupta & R.N.Jha Spirogyra clavata Segar Spirogyra cleveana Transeau Spirogyra colligata Hodgetts Spirogyra columbiana Czurda Spirogyra communis (Hassall) Kützing Spirogyra condensata (Vaucher) Dumortier Spirogyra congolensis Gauthier-Lièvre Spirogyra conspicua F.Gay Spirogyra corrugata Woodhead & Tweed Spirogyra costata Kadlubowska Spirogyra costulata Kadlubowska Spirogyra coumbiana Czurda Spirogyra crassa (Kützing) Kützing Spirogyra crassispina C.-C.Jao Spirogyra crassiuscula (Wittrock & Nordstedt) Transeau Spirogyra crassivallicularis C.-C.Jao Spirogyra crassoidea (Transeau) Transeau Spirogyra crenulata R.N.Singh Spirogyra croasdaleae Blum Spirogyra cylindrica Czurda Spirogyra cylindrosperma (West & G.S.West) H.Krieger Spirogyra cylindrospora West & G.S.West Spirogyra czubinskii Kadlubowska Spirogyra czurdae J.N.Misra Spirogyra czurdiana Kadlubowska Spirogyra daedalea Lagerheim Spirogyra danica Kadlubowska Spirogyra darbhangensis Kargupta & al. Spirogyra decimina (O.F.Müller) Dumortier Spirogyra densa Kützing Spirogyra denticulata Transeau Spirogyra dentireticulata C.-C.Jao Spirogyra desikacharyensis R.S.Rattan Spirogyra dialyderma Ling & Zheng Spirogyra dicephala C.-C.Jao & H.Z.Zhu Spirogyra dictyospora C.-C.Jao Spirogyra diluta H.C.Wood Spirogyra dimorpha Geitler Spirogyra discoidea Transeau Spirogyra discreta Transeau Spirogyra distenta Transeau Spirogyra diversizygotica (V.I.Polyanskij) L.A.Rundina Spirogyra dixitii H.Krieger Spirogyra djalonensis Gauthier-Lièvre Spirogyra djiliense Gauthier-Lièvre Spirogyra drilonensis Petkoff Spirogyra dubia Kützing Spirogyra echinata Tiffany Spirogyra echinospora Blum Spirogyra eillipsospora Transeau Spirogyra elegans Wollny Spirogyra elegantissima Y.J.Ling & Y.M.Zheng Spirogyra ellipsospora Transeau Spirogyra elliptica C.-C.Jao Spirogyra elongata (Vaucher) Dumortier Spirogyra elongata (H.C.Wood) H.C.Wood Spirogyra emilianensis Bonhomme Spirogyra endogranulata O.Bock & W.Bock Spirogyra exilis West & G.S.West Spirogyra fallax (Hansgirg) Wille Spirogyra fassula Zheng Spirogyra favosa Y.-X.Wei & Y.-K.Yung Spirogyra fennica Cedercreutz Spirogyra ferruginea H.W.Liang Spirogyra flavescens (Hassall) Kützing Spirogyra flavicans Kützing Spirogyra fluviatilis Hilse Spirogyra formosa (Transeau) Czurda Spirogyra fossa C.-C.Jao Spirogyra fossulata C.-C.Jao & Hu Spirogyra foveolata (Transeau) Czurda Spirogyra franconica O.Bock & W.Bock Spirogyra frankliniana Tiffany Spirogyra frigida F.Gay Spirogyra fritschiana Czurda Spirogyra fukienica Wei Spirogyra fuscoatra Rabenhorst Spirogyra fuzhouensis H.-J.Hu Spirogyra gallica Petit Spirogyra gangaensis Lakshminarasimhan Spirogyra garlandica Kargupta & R.N.Jha Spirogyra gaterslebensis Reith Spirogyra gauthier-lievrae Kadlubowska Spirogyra gauthieri Gayral Spirogyra gharbensis Gauthier-Lièvre Spirogyra ghosei R.N.Singh Spirogyra gibberosa C.-C.Jao Spirogyra glabra Czurda Spirogyra globulispora Gauthier-Lièvre Spirogyra gobonensis Gauthier-Lièvre Spirogyra godwardiae M.Srivastava Spirogyra goetzei Schmidle Spirogyra gracilis Kützing Spirogyra granulata C.-C.Jao Spirogyra gratiana Transeau Spirogyra groenlandica Rosenvinge Spirogyra guangchowensis Zhu & Zhong Spirogyra guineense Gauthier-Lièvre Spirogyra gujaratensis N.D.Kamat Spirogyra gurdaspurensis R.S.Rattan Spirogyra haimenensis C.-C.Jao Spirogyra hartigii (Kützing) De Toni Spirogyra hassallii (Jenner ex Hassall) P.Crouan & H.Crouan Spirogyra hatillensis Transeau Spirogyra heeriana Nägeli ex Kützing Spirogyra henanensis (L.J.Bi) L.J.Bi Spirogyra herbipolensis O.Bock & W.Bock Spirogyra heterospora Liu Spirogyra hoehnei Borge Spirogyra hoggarica (Gauthier-Lièvre) Gauthier-Lièvre Spirogyra hollandiae Taft Spirogyra hopeiensis C.-C.Jao Spirogyra hunanensis C.-C.Jao Spirogyra hungarica Langer Spirogyra hyalina Cleve Spirogyra hymerae Britton & B.H.Smith Spirogyra inconstans Collins Spirogyra incrassata Czurda Spirogyra indiana Kargupta & R.N.Jha Spirogyra indica Willi Krieger Spirogyra inflata (Vaucher) Dumortier Spirogyra insignis (Hassall) Kützing Spirogyra insueta Zhu & Zhong Spirogyra intermedia Rabenhorst Spirogyra intorta C.-C.Jao Spirogyra ionia Wade Spirogyra irregularis Nägeli ex Kützing Spirogyra islamii Kargupta & P.Sarma Spirogyra ivorensis Gauthier-Lièvre Spirogyra iyengarii Kadlubowska Spirogyra jaoensis Randhawa Spirogyra jaoi S.H.Ley Spirogyra jassiensis (Teodoresco) Czurda Spirogyra jatobae Transeau Spirogyra jogensis M.O.P.Iyengar Spirogyra jugalis (Dillwyn) Kützing Spirogyra juliana Stancheva, J.D.Hall, McCourt & Sheath Spirogyra kaffirita Transeau Spirogyra kamatii Kargupta & P.Sarma Spirogyra karnalae Randhawa Spirogyra khuntiensis A.K.Mahato Spirogyra kolae Hajdu Spirogyra kolhapurensis N.D.Kamat Spirogyra koreana J.-H.Kim, Y.H.Kim, & I.K.Lee Spirogyra krubergii V.J.Poljanski Spirogyra kundaensis R.N.Singh Spirogyra kusheshwarsthanensis Kargupta & P.Sarma Spirogyra kuusamoensis Hirn Spirogyra labbei Gauthier-Lièvre Spirogyra labyrinthica Transeau Spirogyra lacustris Czurda Spirogyra lagerheimii Wittrock Spirogyra laka Kützing Spirogyra lallandiae Taft Spirogyra lambertiana Transeau Spirogyra lamellata (Bhashyakarla Rao) Willi Krieger Spirogyra lamellosa C.-C.Jao Spirogyra lapponica Lagerheim Spirogyra latireticulata Zheng & Ling Spirogyra latviensis Czurda Spirogyra laxa Kützing Spirogyra laxistrata C.-C.Jao Spirogyra lenticularis Transeau Spirogyra lentiformis L.J.Bi Spirogyra lians Transeau Spirogyra libyca Gauthier-Lièvre Spirogyra lineata Suringar Spirogyra lismorensis Playfair Spirogyra lodziensis Kadlubowska Spirogyra longifissa Wei Spirogyra lubrica Kützing Spirogyra lushanensis L.C.Li Spirogyra luteospora Czurda Spirogyra lutetiana Petit Spirogyra lymerae Britton & Smith Spirogyra macrospora (C.B.Rao) Krieger Spirogyra maghrebiana Gauthier-Lièvre Spirogyra magna (Dixit) H.Krieger Spirogyra major Kützing Spirogyra majuscula Kützing Spirogyra malmeana Hirn Spirogyra manoramae Randhawa Spirogyra maravillosa Transeau Spirogyra marchica H.Krieger Spirogyra margalefii Aboal & Llimona Spirogyra margaritata Wollny Spirogyra marocana Gauthier-Lièvre Spirogyra mattonensis (Misra) H.Krieger Spirogyra maxima (Hassall) Wittrock Spirogyra mayyanadensis Ushadevi & Panikkar Spirogyra megaspora Transeau Spirogyra meridionalis W.J.Zhu & Zhong Spirogyra miamiana Taft Spirogyra microdictyon C.-C.Jao & Hu Spirogyra microgranulata C.-C.Jao Spirogyra micropunctata Transeau Spirogyra microspora C.-C.Jao Spirogyra mienningensis L.-C.Li Spirogyra minor (Schmidle) Transeau Spirogyra minuticrassoidea Yamagishi Spirogyra minutifossa C.-C.Jao Spirogyra mirabilis (Hassall) Kützing Spirogyra miranda Kadlubowska Spirogyra mirifica Zheng & Ling Spirogyra mithalaensis A.M.Verma & B.Kumari Spirogyra moebii Transeau Spirogyra monodiana Gauthier-Lièvre Spirogyra montserrati Margalef Spirogyra moulankariensis Usha & Panikkar Spirogyra multiconjugata N.C.Ferrer & E.J.Cáceres Spirogyra multiformis Kadlubowska Spirogyra multistrata Zheng & Ling Spirogyra multitrata Zheng & Ling Spirogyra mutabilis C.-C.Jao & H.J.Hu Spirogyra narcissiana Transeau Spirogyra natchita Transeau Spirogyra neglecta (Hassall) Kützing Spirogyra neorhizobrachialis C.-C.Jao & Zheng Spirogyra nitida (O.F.Müller) Leiblein Spirogyra nodifera O.Bock & W.Bock Spirogyra notabilis Taft Spirogyra nova-angliae Transeau Spirogyra novae-angliae Transeau Spirogyra nyctigama Taft Spirogyra oblata C.-C.Jao Spirogyra oblonga Liu Spirogyra obovata C.-C.Jao Spirogyra occidentalis (Transeau) Czurda Spirogyra oligocarpa C.-C.Jao Spirogyra ollicola C.-C.Jao & Zhong Spirogyra oltmannsii Huber-Pestalozzi Spirogyra orientalis West & G.S.West