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Brachytrichia

Generic name: BRACHYTRICHIA Zanardini ex Bornet et Flahault 1887. Ann. Sci. Nat. Bot., ser. 7, 4: 371.
Synonyms:
HORMACTIS Thuret, 1875. Ann. Sci. Nat.-Bot. 6, 1: 376.[BRACHYTRICHIA Zanardini, Phycearum indicarum Pugillus, p.24, 1872 ex Bornet et Flahault, 1886 : Nostoc, Rivularia, Physactis, Hormactis spec.
Diagnosis:

Bornet et Flahault (1887): Frons initio solida, demum cava, filis nostochineis, in gelatina nidulantibus farcta. Fila flexuoso-curvata, parallela, sursum attenuata et in apicem piliformem desinentia, ramosissima. Pseudo-rami nunc Scytonematum modo gemini li- beri,nunc sursum simplices basi cruribus duobus divergentibus suffulti. Vaginae in junioribus distinctae, tubulosae, demum confluentes obsoletae. Heterocystae intercalares sine ullo ordine positae.
Type species: Brachytrichia quoyi Bornet et Flahault 1887
Descriptions:
Komárek (1992): Filamentous - thallic; thallus flat up to hemispherical, up to 5 cm in diameter, mucilaginous, sometimes crusty, hollow in the center when old, dark green or brownish, composed from horizontal layers of freely tangled or more or less parallely and radially (vertically to the substrate) arranged, true branched trichomes, without loop formations. Sheaths present in young trichomes, colourless or yellowish, absent and diffluent in old trichomes, but filaments enveloped by common, limited mucilage. Trichomes more or less cylindrical in the middle part, uniseriate; trichomes and branches toward the ends continually narrowed, sometimes up to the hairs with narrow,
elongated cells; old trichomes (in old parts of thallus) more freely coiled, thinner, with more elongated and more cylindrical cells; types of true branching: reverse V-type, rarely V-type. Heterocytes intercalar, spherical, barrel-shaped, sometimes shorter or longer than wide, usually wider than vegetative cells. Akinetes missing.
Genotype differences, molecular data:
Reproduction strategies, life cycles, cell division:

Komárek (1992): Cell division cross-wise, in meristematic zones. Reproduction by hormogonia, fhich fragmentate from branches after separation of terminal hairs.
Ultrastructure:
Taxonomic position, higher hierarchy: Cyanophyceae, Nostocales, Symphyonemataceae
Notes to taxonomy, misinterpretations:
Ecology, ecophysiology, ecological significance:
Komárek(1992): Marine, in littoral on stones and shells. Occurs on limestone coasts in tropical and subtropical seas allover the world.
Physiology and biochemistry:
Distribution, endemism, problematic citations:
Reference strain:
Infrageneric scheme, species concept:
List of species:
Brachytrichia balani Bornet et Flahault 1887. Ann. Sci. Nat. Bot., ser. 7, 4: 372
Brachytrichia quoyi Bornet et Flahault 1887. Ann. Sci. Nat. Bot., ser. 7, 4: 373
List
of stains:
Keys:
Application technology:
Drawings:
click to enlargeKomárek (1992)
Literature:

  2.1 taxonomy: Geitler 1932, Geitler 1942, Umezaki 1955, Umezaki 1958, Umezaki 1961, Komárek 1992
  2.2 cytomorphology:
  2.3 16S rRNA sequencing:
  2.4 biology and life cycles:
  2.5 ecology: