''Zygnema'' is a genus of
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does inclu ...
filamentous
thalloid
Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms were ...
alga
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular micr ...
comprising about 100 species.
A terrestrial species, ''Z. terrestre'', is known from India. ''Zygnema'' grows as a free-floating mass of filaments, although young plants may be found anchored to streambeds with a
holdfast. The filaments form a yellow-green to bright green colored tangled mat, and are composed of elongate barrel-shaped cells, each with two star-shaped (stellate)
chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...
s arrayed along the axis of the cell.
Species
Some species include:
*
''Z. atrocoeruleum''
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''Z. binuclearioides''
*
''Z. carinthiacum''
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''Z. carteri''
*
''Z. circumcarinatum''
*
''Z. coeruleum''
*
''Z. conspicuum''
*
''Z. cruciatum''
*
''Z. cyanosphaeroidicum''
*
''Z. cylindricum''
*
''Z. cylindrospermum''
*
''Z. fanicum''
*
''Z. gorakhporense''
*
''Z. insigne''
*
''Z. kashmirense''
*
''Z. kiangsiense''
*
''Z. leiospermum''
*
''Z. melanosporum''
*
''Z. momoniense''
*
''Z. normanii''
*
''Z. oveidanum''
*
''Z. pectinatum''
*
''Z. peliosporum''
*
''Z. quadrispirale''
*
''Z. ralfsii''
*
''Z. rivulare''
*
''Z. ruviatum''
*
''Z. schwabei''
*
''Z. spontaneum''
*
''Z. stagnale''
*
''Z. stellinum''
*
''Z. subtile''
*
''Z. tenue''
*
''Z. tenuissimum''
*
''Z. terrestre''
*
''Z. vaginatum''
*
''Z. vaucherii''
*
''Z. verrucosum''
References
Zygnemataceae
Charophyta genera
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