Oedogonium Link
	From Greek oidos, "swelling" + gonos, "offspring"
Note the distinctive apical rings that form from successive cellular divisions.	Oedogonium is an unbranched, filamentous green alga that is easily identified by the distinctive rings at the apical ends of certain cells. Each cellular division creates a new ring on the cap cell. The cells are cylindrical, sometimes broader at one end, and contain a parietal, netlike chloroplast with several pyrenoids. The cell walls are very hard, which makes them an ideal substrate for epiphytes.   At least 250 Oedogonium species are distinguished by the size of the vegetative cells, the variations in the size and shape of the oogonia, the location of the antheridia, and the variations in patterns on the zygote wall. Over half of the species have been found in the United States.