| zygnema | (n) type genus of the family Zygnemataceae, Syn. genus Zygnema |
| zygnemataceae | (n) pond scums: common freshwater algae forming green slimy masses, Syn. family Zygnemataceae |
| zygnematales | (n) pond scums; desmids, Syn. order Zygnemales, Zygnemales, order Zygnematales |