Chordariales is an order in the Phylum Phaeophyta or brown algae. Member of this order are may be filamentous, crustose with fused cells at the base or they may be terete and differentiated into a central medulla and an outer photosynthetic cortex. They have a sporphytic thallus usually aggregated to form a pseudo parenchyma. As their general name suggests their pigmentation is brown.