The uniseriate trichomes of Tolypothrix are composed of cells that are long and cylindrical or short and barrel-shaped. The cells are blue-green, olive green, yellow, or red in color and sometimes have granules. The filaments are covered by mucilage that varies in thickness and form wooly mats or tufts of filaments that are grayish blue-
green, yellowish, or brownish in color. Young filaments are long with heterocysts at the base and free apical ends. The heterocysts are spherical, cylindrical, or discoid in shape, and have 1-2 pores at their base. Akinetes are rarely observed.