Schizothrix
| Generic name: SCHIZOTHRIX Kützing ex Gomont, 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 292. | ||||||||||
| Synonyms: DICTYOTHRIX Kützing (1843) ex Forti, 1907. Syll. Myxoph., p. 308., HYPHEOTHRIX Kützing, 1843. Phycol. gener., p. 229., HYPHEOTHRIX (Gomont ex Gomont) Kirchner, 1898. In Engler & Prantl, Nat. Pflanzenfam. 1(1a): 67. , INACTIS Kützing, 1843. Phycol. gener.,p. 202., INACTIS Thuret, 1875. Ann. Sci. Nar.-Bot. 6, 1: 375., INOMERIA Kützing, 1845. Phycol. german., p. 191., SCHIZODICTYON Kützing, 1943. Phycol. gener., p. 230.[SCHIZOTHRIX Kützing, Phycologia gener., p. 230, 1843 ex Gomont, 1892: Oscillatoria, Scytonema, Nostoc, Leptomitus, Calothrix, Symploca, Symphyosiphon, Symphyothrix, Schizodictyon, Ionomeria, Inactis, Hypheothrix, Leptothrix, Leibleinia, Phormidium, Hydrocoleum, Schizosiphon, Microcoleus, Lyngbya, Hormosiphon spec.] | ||||||||||
| Diagnosis: Gomont (1892): Fila pulvinulos definitos, saepe calce induralos, aut fasciculos erectos, prostratos vel fluctuantes formantia, aut in stratum pannosum intricata, saepe inferne trunciformia, superne crebre, rarius parce pseudo-ramosa et subsimplicia. Vaginae hyalinae, luteo-fuscae vel purpureae, passim caeruleae, firmae, lamellosae, apice acuminatae, chlorozincico iodurato in speciebus fere cunctis caerulescentes. Trichomata intra vaginam pauca, plus minusve laxe aggregata; articuli diametro trichomatis saepius longiores, nunquam eo multo breviores; apex trichomatis rectus, plerumque attenuatus, haud capitatus. Membrana cellulae apicalis superne non incrassata. Plantae terrestres vel aquaticae, nunquam omnino marinae, frequenter in stillicidiis vigentes. |
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| Type species: Schizothrix fuscescens Kutzing ex Gomont 1892. - More than 80 species classified usually into several subgenera or sections, from which two (Symplocastrum and Inactis) represent probably special genera; the section "Chromosiphon" is without taxonomic value. | ||||||||||
| Descriptions: Komárek (1992): Filamentous - colonial; filaments polarized, thick, containing rarely one, usually several more or less parallely situated trichomes; sheaths fine, slightly or clearly widened, gelatinous, homogeneous, rarely layered or lamellated, with straight or irregularly wavy, limited margin; sometimes fine special sheaths enveloping the simple trichomes occur; sheaths colour1ess or partly coloured, yellow, yellowish-brown, reddish or blue- violet; ends of sheaths characteristically narrowed and bluntly pointed, usually closed, sometimes branched. Filaments in free divaricated, microscopic or up to macroscopic filamentous thallus (subg. Schizothrix), joined in erected fascicles (subg. Symplocastrum Gomont 1892), or incrusted heavily by calcium carbonate and forming more or less hard, hemispherical or layered colonies on the (usually stony) substrate (subg. Inactis (Kutzing) Gomont 1892). Thallus usually joined to the substrate, rarely free (in soil or metaphyton). Trichomes cylindrical, isopolar, not polarized (in contrast to filaments I), usually not attenuated to the ends, unconstricted or slightly constricted at the cross-walls. Cells cylindrical, rarely more or less isodiametrical, usually longer than wide; apical cells mainly conical and rounded, without calyptra and without thickened outer cell wall. Heterocytes and akinetes missing. |
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| Reproduction strategies, life cycles, cell division: Komárek (1992): Cell division crosswise to the trichome axis, without meristematic zone; all cells capable to divide. Reproduction by motile hormogonia, which separate from trichomes probably without help of necridic cells. |
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| Taxonomic position, higher hierarchy: Cyanophyceae, Oscillatoriales, Schizotrichaceae Notes to taxonomy, misinterpretations: |
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| Ecology, ecophysiology, ecological significance: Komárek (1992): Many species grow in littoral of lakes joined to the stony or wooden substrates (usually in surf zone) or in metaphyton among water plants and in moors and swamps. Characteristical are the Inactis-species, forming crusty hemispherical colonies or layers on stones and rocks in littoral zone of lakes, streaming water or on wet rocks, usually in limestone areas. Several species are known from sea coasts and salty biotopes, other live in springs, mineral and thermal springs or in waterfalls. Aerophytic species grow also in wet soils, often in moors. Several representants of the subg. Symplocastrum form characteristical mats with erected Symploca-like fascicles on wet, not polluted forest soils or old wooden substrates. The species from the section Hypheothrix (Kutzing) Lemmermann belong probably to the genus Phormidium. Gomont (1892): Plantae terrestres vel aquaticae, nunquam omnino marinae, frequenter in stillicidiis vigentes. |
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| List of species: subgenus Schizothrix Schizothrix affinis Lemmermann 1904 Schizothrix aikenensis Wolle ex Philson 1939 Schizothrix antarctica Fritsch 1917 Schizothrix arenaria Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 312 Schizothrix calcicola Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 307 Schizothrix cuspidata (W. et G.S. West) W. et G.S. West 1896 Schizothrix delicatissima W. et G.S. West 1897 Schizothrix diplosiphon (Voronichin) Anagnostidis 2001 Schizothrix elongata W. et G.S. West 1897 Schizothrix epilithica (Ercegović) Anagnostidis 2001 Schizothrix epiphytica Fritsch in Fritsch et Rich 1923 Schizothrix ericetorum Lemmermann 1910 Schizothrix facilis (Skuja) Anagnostidis 2001 Schizothrix flammea Komárek et M. Watanabe 1998 Schizothrix fragilis Kützing ex Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 314 Schizothrix fritschii Anand 1937 Schizothrix funalis W. et G.S. West 1896 Schizothrix funicilus Voronichin 1932 Schizothrix fuscescens Kützing ex Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 324 Schizothrix gomontii Weber van Bosse 1913 Schizothrix gracilis Golubić 1973 Schizothrix hawaiensis Lemmermann 1905 Schizothrix helva Frémy 1939 Schizothrix heufleri Grunow ex Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 325 Schizothrix kerguelensis Wille 1901 Schizothrix kialingensis Jao 1944 Schizothrix kwangsiensis Jao 1944 Schizothrix lacustris A. Braun ex Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 301 Schizothrix lardacea Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 311 Shcizothrix lenormandiana Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 312 Schizothrix longearticulata (Geitler) Anagnostidis 2001 Schizothrix lutea Frémy 1930 Schizothrix luteola Duvigneaud et Symoens 1949 Schizothrix macbridei Drouet 1943 Schizothrix martima Yoneda 1939 Schizothrix mellea Gardner 1927 Schizothrix minor (Gardner) Anagnostidis 2001 Schizothrix nasrii Frémy in Frémy et Nasr 1938 Schizothrix radius-solis M. Watanabe et Komárek 1994 Schizothrix rivulariarum Voronichin 1932 Schizothrix rubra Meneghini ex Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 315 Schizothrix septentrionalis Gomont 1899 Schizothrix simmonsiae Collins 1906 Schizothrix simplicior Skuja 1964 Schizothrix symplocoides (Gardner) Geitler 1932 Schizothrix tenuis Voronichin 1923 Schizothrix thermophila Copeland 1936 Schizothrix tinctoria Gomont ex Gomont 1892. Ann. Sci. Nat. Bot., ser. 7, 15: 303 Schizothrix viguieri Frémy 1930 Schizothrix violacea Gardner 1927 Schizothrix yellowstonensis (Copeland) Anagnostidis et Komárek 2001 subgenus Inactis Thuret ex Gomont 1892 Unclear taxa: |
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Drawings: Komárek 1992 |
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