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 Individual filaments are microscopic (magnification is needed to see any detail) 3. Are the filaments branched or unbranched? Filaments are unbranched Filaments are branched (although branches may be rare), including false branching and filaments united at base on substrate