Oedogoniaceae

The Oedogoniales are an order of filamentous freshwater green algae of the class Chlorophyceae. The order is well-defined and has several unique features, including asexual reproduction with zoospores that possess stephanokont flagella: numerous short flagella arranged in a subapical whorl. The oedogoniales have a highly specialized type of oogamy, and an elaborate method of cell division which results in the accumulation of apical caps.
The order comprises one family, Oedogoniaceae, with three genera. Some common features among these genera may be obscure. The hairs of "Bulbochaete" and the heterotrichous system "Oedocladium" are similar to Chaetophorales, with which they may share a distant relationship. Of the genus "Oedogonium" there are over 330 species, about 70 species of "Bulbochaete", and 10 species of "Oedocladium". More than half of these species are known to North America. Many of the species are used by aquarium owners.
Members of the order usually inhabit still waters such as lakes and ponds, rather than rivers and streams. The oedogoniales include free-living and epiphytic members on other algae or freshwater angiosperms.