Some Zygnemataceae (Chlorophyta) of Ontario, Canada, including descriptions of two new species
We examined 1455 filamentous algal samples collected from 32 Ontario sites since 1981 and identified 21 Zygnemataceae, including two new species: Spirogyra favosa Wei et Yung sp.nov. and Zygnema lacustre Wei et Yung sp.nov. Of the 21 taxa described in this paper, Zygogonium tunetanum, Temnogametum tirupatiense, Mougeotia quadragulata, and Spirogyra fennica were the important species in the acidic sites, whereas Mougeotia laetevirens, Zygnemopsis stephensiae, and Spirogyra jatobae were common in the circumneutral and alkaline locations. Zygogonium tunetanum was the most important metaphytic alga in lakes with pH 6.8 and lower, proliferating in the littoral areas of acidic Ontario lakes. These data support the view that the taxonomy of Zygnemataceae should place more emphasis on the zygospore wall structures and ornamentations and less emphasis on the dimensions of vegetative cells.