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 » Filamentous » Filaments microscopic » Filaments are unbranched » Chloroplasts visible inside cells are green or yellow-green Chloroplasts visible inside cells are green or yellow-green 5. Please select the cell wall details. Some cell walls have cell division scars visible at one end; pyrenoids present in chloroplasts Oedogonium Cell wall is smooth and featureless; filaments are short and easily dissociated; chloroplasts one to a few per cell, small and discoid. Stichococcus Cells have constrictions between them (filamentous desmids) Cell walls composed of overlapping pieces that are H-shaped in optical section (often visible at break points); pyrenoids absent from chloroplasts Cell wall is smooth and featureless; filaments are long and cells are not easily dissociated.