1) Genus zygnema 2) Protoctist genus 
Zygnema is a genus of freshwater filamentous thalloid alga 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 ...
[n] - type genus of the family Zygnemataceae
genus Zygnema noun type genus of the family Zygnemataceae