Micrasterias pinnatifida Ralfs 1848

    Cells medium to large size, as long as broad, measures 56-71 µm in long and 65-79 µm in broad. Cell deeply constricted at the center, sinus very linear and open triangular outwardly, isthmus 12-16μm. Semicells with polar and lateral lobes; polar lobes with narrow base and expanded horizontally with truncate or lightly curved apices, polar lobes minutely bifid, polar lobe smaller than lateral lobe. Lateral lobes larger size, horizontally expanded and sub-fusiform; apex minutely bifid. Cell wall punctuate; semicells narrowly ovate-pyramidate in lateral view; rhomboid-lanceolate in vertical view.