Description

 Filaments are simple, tapering towards the base and up to 10 cm long. It forms a very fine felt-like covering that varies in colour from dark green to purple and adheres closely to damp, shady surfaces. In good years this 'felt' is dark and conspicuous but in others barely detectable. Growth varies seasonally and is maximum in the early months of the year.The large cell size of this species distinguishes it from other Ulothrix and Urospora species. The three varieties of thallus include, filamentous; dwarf filamentous and unicellular Codiolum-like.