Diagnostic features
Unbranched filamentous chlorophyte with cylindrical cells, some of which have rings or scars near the ends, formed during past cell divisions (also characteristic of Bulbochaete, to which it is closely related). Attached to surfaces by a holdfast, which is commonly surrounded by reddish material, but filaments may be long and this feature may not be collected. Chloroplast netlike, parietal, completely encircling the cell, and containing one or more pyrenoids. Life cycle may be extremely complex, and varies by species. Oogonia large and round, antheridia very short (same width as vegetative cells). Simplest type involves both sexes on the same filament, but they may occur on separate filaments, and dwarf males occur in some species. Reproductive structures only occasionally found in field material.
![[Oedogonium], Shag River, north Otago. Photo: Otago Regional Council & Manaaki Whenua Image](/assets/Tools-And-Resources/Identification/algae/oedogonium3__ScaleWidthWzEwMjRd.jpg)
![[Oedogonium], Shag River, north Otago, X320. Photo: Otago Regional Council & Manaaki Whenua Image](/assets/Tools-And-Resources/Identification/algae/oedogonium320__ScaleWidthWzEwMjRd.jpg)