Photo-autotrophs with pigmentaion similar to the cyanobacteria (chlorophyll a only, & phycobilins). Flagella and cilia are totally absent in the group. Most are marine "seaweeeds". members of this group provide us with commercially important products such as agar and carrageenan. Most people have never heard of carrageenan but check the ingredients label next time you eat ice cream or drink chocolate milk.