Family Description:
Since this order contains just one family in the local area, the Cladophoraceae, the characteristics of this family are the same as those of the order. Members of the genera Chaetomorpha and Rhizoclonium have unbranched filaments, whereas members of Cladophora have branched filaments.

Species description:
The dark green filaments are up to 35 cm (14.5 in) in length and are unbranched and twisted.

All cells are cylindrical (40 to 50 µm in diameter and three to five times that length). Rhizoidal branches are either lacking, or, if present, they are composed of a single cell that arises from a basal cell of the filament.

This species often forms dense, tangled growths that float on the surface of the water or lie loosely on the bottom of mid intertidal tidepools. It is also sometimes observed on mudflats at low tide.

This species is closely related to the genus Chaetomorpha and is sometimes included in that genus. The species of Chaetomorpha have larger cells than do those of Rhizoclonium. Some, in fact, are so large they can be seen with the naked eye. Up to seven species of Chaetomorpha are recognized to occur in the northeast Pacific Ocean, whereas only two or three Rhizoclonium species are recorded here.

Source:  North Pacific Seaweeds

Synonyms and Alternate Names:
Conferva tortuosa