[Algae of the division Rhodophyta, in which the red pigment (PHYCOERYTHRIN) predominates. However if this pigment is destroyed, the algae can appear purple, brown, green, or yellow. Two important substances found in the cell walls of red algae are AGAR and CARRAGEENAN. Red algae are thought to be closely related to the prokaryotic CYANOBACTERIA. ( MSH )]
UMLS (CSP) C0002033