Description
''Polysiphonia'' is a red alga, polysiphonous and usually well branched, with some plants reaching a length of about 30 cm. They are attached by rhizoids or Holdfast (biology), haptera to a rocky surface or other alga. The thallus (tissue) consists of fine branched filaments each with a central axial filament supporting pericentral cells. The number of these pericentral cells (4–24) is used in identification. ''Polysiphonia elongata'' shows a central axial cell with 4 periaxial cells with cortical cells growing over the outside on the older fronds. Its cuticle contains bromine. Features used in identification include the number of pericentral cells, the cortication of main branches, constriction of young branches at their base, whether the branching Glossary of botanical terms#dichotomous, dichotomous or Glossary of botanical terms#spiral, spiral, and the width and length of thalli.Distribution and ecology
Species have been recorded from Europe, Australia and New Zealand, North America and South America, islands in the Pacific Ocean, South Africa, southwest Asia, Japan, Greenland and Antarctica. The species are entirely marine, found growing on rock, other algae, mussels or limpets and artificial substrata etc. from mid-Littoral zone, littoral to at least 27 m depth. Many species are abundant in Tide pool, rock pools. ''Polysiphonia lanosa'' is commonly found growing on ''Ascophyllum nodosum.''Reproduction and life cycle
The life-cycle of the red algae has three stages (wikt:triphasic, triphasic). In ''Polysiphonia'' it consists of a sequence of a gametangium, gametangial, carpospore, carpospoangial and Red algae#Life cycle, tetrasporangial phases.Smith, G.M. 1955. ''Cryptogamic Botany Algae and Fungi. Volume 1.'' Second Edition. p.337 Male (Ploidy#Haploid and monoploid, haploid) plants (the male gametophytes) produce spermatia and the female plants (the female gametophytes) produce the carpogonium (the haploid carpogonium) which remains attached to the parent female plant. After fertilization the Ploidy#Diploid, diploid Cell nucleus, nucleus migrates and fuses with an auxiliary cell. A complex series of fusions and developments follow as the diploid zygote develops to become the carposporophyte, this is a separate phase of the life-cycle and is entirely parasitism, parasitic on the female, it is surrounded by the haploid pericarp of the parent female plant. The diploid carpospores produced in the carposporangium when released are non-motile, they settle and grow to form filamentous diploid plants similar to the gametophyte. This diploid plant is the tetrasporaphyte, tetrasporophyte which when adult produced spores in fours after meiosis. These spores settle and grow to become the male and female plants thus completing the cycle.Species
The species currently recognized are: *''Polysiphonia abscissa, P. abscissa'' *''Polysiphonia abscissoides, P. abscissoides'' *''Polysiphonia acanthina, P. acanthina'' *''Polysiphonia acuminata, P. acuminata'' *''Polysiphonia adamsiae, P. adamsiae'' *''Polysiphonia adriatica, P. adriatica'' *''Polysiphonia amphibolis, P. amphibolis'' *''Polysiphonia anisogona, P. anisogona'' *''Polysiphonia anomala, P. anomala'' *''Polysiphonia arachnoidea, P. arachnoidea'' *''Polysiphonia arctica, P. arctica'' *''Polysiphonia aterrima, P. aterrima'' *''Polysiphonia atlantica, P. atlantica'' *''Polysiphonia atra, P. atra'' *''Polysiphonia atricapilla, P. atricapilla'' *''Polysiphonia australiensis, P. australiensis'' *''Polysiphonia azorica, P. azorica'' *''Polysiphonia bajacali, P. bajacali'' *''Polysiphonia banyulensis, P. banyulensis'' *''Polysiphonia barbatula, P. barbatula'' *''Polysiphonia baxteri, P. baxteri'' *''Polysiphonia beaudettei, P. beaudettei'' *''Polysiphonia beguinotii, P. beguinotii'' *''Polysiphonia bicornis, P. bicornis'' *''Polysiphonia biformis, P. biformis'' *''Polysiphonia bifurcata, P. bifurcata'' *''Polysiphonia binneyi, P. binneyi'' *''Polysiphonia blandii, P. blandii'' *''Polysiphonia boergesenii, P. boergesenii'' *''Polysiphonia boldii, P. boldii'' *''Polysiphonia breviarticulata, P. breviarticulata'' *''Polysiphonia brevisegmenta, P. brevisegmenta'' *''Polysiphonia brodiei, P. brodiei'' *''Polysiphonia caespitosa, P. caespitosa'' *''Polysiphonia callithamnioides, P. callithamnioides'' *''Polysiphonia cancellata, P. cancellata'' *''Polysiphonia capucina, P. capucina'' *''Polysiphonia carettia, P. carettia'' *''Polysiphonia caspica, P. caspica'' *''Polysiphonia castagnei, P. castagnei'' *''Polysiphonia castelliana, P. castelliana'' *''Polysiphonia ceramiaeformis, P. ceramiaeformis'' *''Polysiphonia cladorhiza, P. cladorhiza'' *''Polysiphonia coacta, P. coacta'' *''Polysiphonia codicola, P. codicola'' *''Polysiphonia collinsii, P. collinsii'' *''Polysiphonia confusa, P. confusa'' *''Polysiphonia constricta, P. constricta'' *''Polysiphonia corymbosa, P. corymbosa'' *''Polysiphonia crassa, P. crassa'' *''Polysiphonia crassicollis, P. crassicollis'' *''Polysiphonia crassiuscula, P. crassiuscula'' *''Polysiphonia curta, P. curta'' *''Polysiphonia dasyoeformis, P. dasyoeformis'' *''Polysiphonia daveyae, P. daveyae'' *''Polysiphonia decipiens, P. decipiens'' *''Polysiphonia decussata, P. decussata'' *''Polysiphonia delicatula, P. delicatula'' *''Polysiphonia denudata, P. denudata'' *''Polysiphonia derbesii, P. derbesii'' *''Polysiphonia deusta, P. deusta'' *''Polysiphonia devoniensis, P. devoniensis'' *''Polysiphonia dichotoma, P. dichotoma'' *''Polysiphonia dotyi, P. dotyi'' *''Polysiphonia dumosa, P. dumosa'' *''Polysiphonia echigoensis, P. echigoensis'' *''Polysiphonia echinata, P. echinata'' *''Polysiphonia elongata, P. elongata'' - lobster horns *''Polysiphonia elongella, P. elongella'' *''Polysiphonia erythraea, P. erythraea'' *''Polysiphonia exilis, P. exilis'' *''Polysiphonia fernandeziana, P. fernandeziana'' *''Polysiphonia fibrata, P. fibrata'' *''Polysiphonia fibrillosa, P. fibrillosa'' *''Polysiphonia figariana, P. figariana'' *''Polysiphonia flabelliformis, P. flabelliformis'' *''Polysiphonia flabellulata, P. flabellulata'' *''Polysiphonia flexella, P. flexella'' *''Polysiphonia flexicaulis, P. flexicaulis'' *''Polysiphonia flocculosa, P. flocculosa'' *''Polysiphonia foeniculacea, P. foeniculacea'' *''Polysiphonia foetidissima, P. foetidissima'' *''Polysiphonia forfex, P. forfex'' *''Polysiphonia fracta, P. fracta'' *''Polysiphonia fragilis, P. fragilis'' *''Polysiphonia fucoides, P. fucoides'' *''Polysiphonia funebris, P. funebris'' *''Polysiphonia furcellata, P. furcellata'' *''Polysiphonia fuscorubens, P. fuscorubens'' *''Polysiphonia gonatophora, P. gonatophora'' *''Polysiphonia gracilis, P. gracilis'' *''Polysiphonia guadalupensis, P. guadalupensis'' *''Polysiphonia guernisacii, P. guernisacii'' *''Polysiphonia hancockii, P. hancockii'' *''Polysiphonia hapalacantha, P. hapalacantha'' *''Polysiphonia haplodasyae, P. haplodasyae'' *''Polysiphonia hassleri, P. hassleri'' *''Polysiphonia havanensis, P. havanensis'' *''Polysiphonia havaniensis, P. havaniensis'' *''Polysiphonia hemisphaerica, P. hemisphaerica'' *''Polysiphonia hendryi, P. hendryi'' *''Polysiphonia herpa, P. herpa'' *''Polysiphonia hirta, P. hirta'' *''Polysiphonia hochstetteriana, P. hochstetteriana'' *''Polysiphonia hockstetteriana, P. hockstetteriana'' *''Polysiphonia homoia, P. homoia'' *''Polysiphonia howei, P. howei'' *''Polysiphonia implexa, P. implexa'' *''Polysiphonia incompta, P. incompta'' *''Polysiphonia indigena, P. indigena'' *''Polysiphonia infestans, P. infestans'' *''Polysiphonia isogona, P. isogona'' *''Polysiphonia japonica, P. japonica'' *''Polysiphonia johnstonii, P. johnstonii'' *''Polysiphonia kampsaxii, P. kampsaxii'' *''Polysiphonia kappannae, P. kappannae'' *''Polysiphonia kieliana, P. kieliana'' *''Polysiphonia kotschyana, P. kotschyana'' *''Polysiphonia kowiensis, P. kowiensis'' *''Polysiphonia lanosa, P. lanosa'' *''Polysiphonia letestui, P. letestui'' *''Polysiphonia macounii, P. macounii'' *''Polysiphonia marchantae, P. marchantae'' *''Polysiphonia masonii, P. masonii'' *''Polysiphonia mollis, P. mollis'' *''Polysiphonia morrowii, P. morrowii'' *''Polysiphonia mottei, P. mottei'' *''Polysiphonia muelleriana, P. muelleriana'' *''Polysiphonia namibiensis, P. namibiensis'' *''Polysiphonia nathanielii, P. nathanielii'' *''Polysiphonia neglecta, P. neglecta'' *''Polysiphonia nhatrangense, P. nhatrangense'' *''Polysiphonia nhatrangensis, P. nhatrangensis'' *''Polysiphonia nigra, P. nigra'' *''Polysiphonia nigrescens, P. nigrescens'' *''Polysiphonia nizamuddinii, P. nizamuddinii'' *''Polysiphonia opaca, P. opaca'' *''Polysiphonia ornata, P. ornata'' *''Polysiphonia orthocarpa, P. orthocarpa'' *''Polysiphonia pacifica, P. pacifica'' *''Polysiphonia paniculata, P. paniculata'' *''Polysiphonia paradoxa, P. paradoxa'' *''Polysiphonia parthasarathyi, P. parthasarathyi'' *''Polysiphonia parvula, P. parvula'' *''Polysiphonia pentamera, P. pentamera'' *''Polysiphonia perforans, P. perforans'' *''Polysiphonia pernacola, P. pernacola'' *''Polysiphonia perriniae, P. perriniae'' *''Polysiphonia platycarpa, P. platycarpa'' *''Polysiphonia plectocarpa, P. plectocarpa'' *''Polysiphonia plectrocarpa, P. plectrocarpa'' *''Polysiphonia polychroma, P. polychroma'' *''Polysiphonia polyspora, P. polyspora'' *''Polysiphonia porrecta, P. porrecta'' *''Polysiphonia propagulifera, P. propagulifera'' *''Polysiphonia pseudovillum, P. pseudovillum'' *''Polysiphonia pulvinata, P. pulvinata'' *''Polysiphonia quadrata, P. quadrata'' *''Polysiphonia ramentacea, P. ramentacea'' *''Polysiphonia requienii, P. requienii'' *''Polysiphonia rhododactyla, P. rhododactyla'' *''Polysiphonia rhunensis, P. rhunensis'' *''Polysiphonia rigidula, P. rigidula'' *''Polysiphonia rudis, P. rudis'' *''Polysiphonia saccorhiza, P. saccorhiza'' *''Polysiphonia sadoensis, P. sadoensis'' *''Polysiphonia sanguinea, P. sanguinea'' *''Polysiphonia scopulorum, P. scopulorum'' *''Polysiphonia senticulosa, P. senticulosa'' *''Polysiphonia sertularioides, P. sertularioides'' *''Polysiphonia setigera, P. setigera'' *''Polysiphonia shepherdii, P. shepherdii'' *''Polysiphonia simplex, P. simplex'' *''Polysiphonia simulans, P. simulans'' *''Polysiphonia sinicola, P. sinicola'' *''Polysiphonia sonorensis, P. sonorensis'' *''Polysiphonia sparsa, P. sparsa'' *''Polysiphonia sphaerocarpa, P. sphaerocarpa'' *''Polysiphonia spinosa, P. spinosa'' *''Polysiphonia stricta, P. stricta'' *''Polysiphonia strictissima, P. strictissima'' *''Polysiphonia stuposa, P. stuposa'' *''Polysiphonia subtilissima, P. subtilissima'' *''Polysiphonia subulata, P. subulata'' *''Polysiphonia subulifera, P. subulifera'' *''Polysiphonia succulenta, P. succulenta'' *''Polysiphonia tapinocarpa, P. tapinocarpa'' *''Polysiphonia teges, P. teges'' *''Polysiphonia tenerrima, P. tenerrima'' *''Polysiphonia tenuistriata, P. tenuistriata'' *''Polysiphonia tepida, P. tepida'' *''Polysiphonia tokidae, P. tokidae'' *''Polysiphonia tongatensis, P. tongatensis'' *''Polysiphonia tripinnata, P. tripinnata'' *''Polysiphonia triton, P. triton'' *''Polysiphonia tsudana, P. tsudana'' *''Polysiphonia tuberosa, P. tuberosa'' *''Polysiphonia tuticorinensis, P. tuticorinensis'' *''Polysiphonia unguiformis, P. unguiformis'' *''Polysiphonia upolensis, P. upolensis'' *''Polysiphonia urbana, P. urbana'' *''Polysiphonia urbanoides, P. urbanoides'' *''Polysiphonia urceolata, P. urceolata'' *''Polysiphonia utricularis, P. utricularis'' *''Polysiphonia virgata, P. virgata'' *''Polysiphonia yonakuniensis, P. yonakuniensis''Notes
References
External links