A phylum (or group, i.e. the rhodophytes) of algae that are often pink or red in colour due to the presence of the pigments phycocyanin and phycoerythrin. Members of the Rhodophyta may be unicellular or multicellular; the latter form branched flattened thalli or filaments. They are commonly found along the coasts of tropical areas. Sexual reproduction is by means of carpospores (see carpogonium). Red algae are now regarded as members of the eukaryote assemblage Archaeplastida: see plant (sense 2).