Tweet this page Like this page Email this page Share this page Home» Resources » Identification » Identification of algae » Freshwater algae » How to identify algae » Identification guide » Colonial » Cell contents (chloroplasts when present) are green or blue-green » Cells contain membrane-bound organelles (chloroplasts, nuclei etc) and cell contents are grass green » Colony comprised of cells in flat sheets or skeins; cells lack contrictions Colony comprised of cells in flat sheets or skeins; cells lack contrictions Sheet fragments into ribbons, due to cells arranged in parallel rows. Parallela Extensive flat blade or sac, attached to surfaces by a holdfast. Monostroma A small, roundish flat disc of cells. Coleochaete