A solitary trichome enclosed in a firm sheath, which can be either clear or yellowish in appearance. These filaments can be either planktonic (free-floating) or agglutinated (clumped together). The trichome itself is blue-green and can have a twisted or straight configuration, without tapering at the ends. There is a noticeable constriction at the septum, and no rows of granules are present. The trichome can be easily separated into individual cells, with each cell body measuring 2.3-16 μm in length and 2.3-4 μm in width.