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Dichothrix

Generic name: DICHOTHRIX Zanardini ex Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 373
Synonyms:
[ DICHOTHRIX Zanardini, Plantarum maris rubri Enumeratio, p. 89, 1858 : Scytonema, Calothrix, Schizosiphon, Mastichonema, Lyngbya, Symphyosiphon sp.]
Diagnosis:
Bornet et Flahault (1886): Fila subdichotome divisa; trichomata saepe pluria (2-6) in vagina communi inclusa. Heterocystae nunc basilares , nunc intercalares, in unica specie nullae. Caespites penicillati vel pulvinati.
Type species: Dichothrix penicillata Zanardini ex Bornet et Flahault 1886
Descriptions:
Komárek (1992): Filamentous - thallous; filaments heteropolar, differentiated into basal and apical parts, obligatory commonly falsely branched, solitary or in fasciculated colonies or strata; false branching lateral, always with only one branch, growing usually at first parallely with original trichome, later diverging. Trichomes and branches with basal heterocytes, rarely develop intercalar heterocytes, solitary or (rarely) in twos; heterocytes usually heteropolar (unipored). Sheaths always present, usually firm, colourless or yellow-brown and lamellated, at the end joined to the trichome or widened and diverging. Trichomes with cylindrical or barrel-shaped cells, at the cross walls constricted or unconstricted, hair-like narrowed to the apical ends; hairs are composed from a row of long, narrow, hyaline cells. Aerotopes and akinetes lacking.
Genotype differences, molecular data:
Reproduction strategies, life cycles, cell division:
Komárek (1992):Division of cells perpendicularly to the long axis of a trichome (sometimes meristematic zones), disintegration of trichomes at intercalar heterocytes before false branching. Reproduction by hormogonia, which divide from trichomes by help of necridic cells after separation of the terminal hair.
Ultrastructure:
Taxonomic position, higher hierarchy: Cyanophyceae, Nostocales, Rivulariaceae
Notes to taxonomy, misinterpretations:
Ecology, ecophysiology, ecological significance:
Komárek (1992):The majority of species live periphytically on stones or on water plants in clear waterfalls, streaming water, on wet stony walls and in littorals of water reservoirs. Several species are known from marine littoral.
Bornet et Flahault (1886): Plantae marinae vel aquae dulcis.
Physiology and biochemistry:
Distribution, endemism, problematic citations:
Reference strain:
Infrageneric scheme, species
concept:

List of species:
Dichothrix austrogeorgica Carlson 1913
Dichothrix baueriana (Grunow) Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 375
Dichothrix bornetiana Howe 1924
Dichothrix calcarea Tilden 1897
Dichothrix chungii Gardner 1927
Dichothrix compacta Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 378
Dichothrix elongata Compère 1970
Dichothrix eylatensis Rays et Dor 1963
Dichothrix fucicola (Kützing) Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 379
Dichothrix fusca Fritsch 1917
Dichothrix gelatinosa Böcher 1946
Dichothrix gypsophila (Kützing) Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 377
Dichothrix hamata Jao 1939
Dichothrix handelii Skuja 1937
Dichothrix hemisphaerica Jao 1943
Dichothrix hosfordii (Wolle) Bornet et Flahault 1896
Dichothrix interrupta W. et G.S. West 1884
Dichothrix inyoensis Drouet 1943
Dichothrix minima Setchell et Gardner 1919
Dichothrix montana Tilden 1902
Dichothrix nordstedtii Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 374
Dichothrix ledereri Skácelová 2006. Arch. Hydrobiol./Algological Studies 121:7
Dichothrix olivacea Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 375
Dichothrix orsiniana Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 376
Dichothrix penicillata Zanardini ex Bornet et Flahault 1886. Ann. Sci. Nat. Bot., ser. 7, 3: 379
Dichothrix ramenskii Elenkin 1922
Dichothrix rupicola Collins 1901
Dichothrix sacconemoides Jao et Lee 1974
Dichothrix schweickerdtii Cholnoky 1955
Dichothrix seriata Setchell et Gardner 1918
Dichothrix sinensis Jao 1939

Dichothrix spiralis Fritsch 1957
Dichothrix subdichotoma Voronichin 1923
Dichothrix utahensis Tilden 1898
Dichothrix willei Gardner 1927

Unclear taxa:
Calothrix crustacea Thuret sensu Frémy 1928
Calothrix dolichomeres Skuja 1949
Calothrix fasciculata [Agardh 1824] ex Bornet et Flahault
Calothrix intorta Jao 1939
Dichothrix bivaginata Frémy 1935
Dichothrix catalaunica Gonzalez-Guerrero 1930
Dichothrix cavanillesii Gonzalez-Guerrero 1946
Dichothrix compacta var. calcarata sensu Golubić 1967
Dichothrix meneghiniana [Kützing] Forti 1911
Schizothrix kerguelensis Reinsch 1876

Keys:
List of stains:
Drawings:
Komárek
1992
Application technology:
Literature:

  2.1 taxonomy: Geitler 1932, Geitler 1942, Komárek 1992, Skácelová 2006
  2.2 cytomorphology:
  2.3 16S rRNA sequencing:
  2.4 biology and life cycles:
  2.5 ecology: