''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. The term excludes seawater and brackish water, but it does include non-salty mi ...
filamentous
thalloid alga
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...
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, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...
s arrayed along the axis of the cell.
Species
Some species include:
*
''Z. atrocoeruleum''
*
''Z. binuclearioides''
*
''Z. carinthiacum''
*
''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
{{green alga-stub