Rhodophyta: More on Morphology

While some rhodophytes are unicellular, most species grow as filaments, such as those shown below at right, or membranous sheets of cells. Some of these multicellular forms are coralline, depositing skeletons composed of calcium carbonate crystals within and around their cell walls. These calcified reds can be difficult to distinguish from corals without the assistance of a microscope or a trained eye, as you can see from the picture below at left.

Rhodophytes store their energy surplus from photosynthesis in the form of floridean starch, a carbohydrate assembled from approximately 15 glucose units. This carbohydrate, like the pigments of the red algae, are unique to this group. The cells of rhodophytes are commonly covered by a slimy outer sheath. Additional colloidal compounds may be found in the cell wall, such compounds as agars and carageenan.

The red "algae" lack flagella at all stages in their life history, and cells may be multinucleate.

These images of rhodophytes provided courtesy of the University of Wisconsin - La Crosse.