Fortiea DeToni (1936: 3)

Mcgregor, Glenn B., 2018, Freshwater Cyanobacteria of North-Eastern Australia: 3. Nostocales, Phytotaxa 359 (1), pp. 448-450 : 448-450

Fortiea DeToni (1936: 3)

Type: F. caucasica (Elenkin) De Toni (1936: 3)

Filamentous; heteropolar, differentiated into a basal part with a terminal heterocyte and free apical end, cylindrical, simple, solitary or in small groups; filaments usually creeping along the substratum or amongst the periphyton. Sheaths firm, always one per trichome, colourless, sometimes thickened and lamellated. Trichomes cylindrical or slightly widened at the base, narrowed in the middle part and clearly widened at the ends, constricted or unconstricted at the cross walls, but usually constricted at the ends. Vegetative cells cylindrical or barrel-shaped, in the central parts of the trichome usually longer than wide, at the bases and at the apices isodiametric or shorter than wide; apical cells widely rounded or spherical. Akinetes, usually in rows and separated by heterocytes. Cell division crosswise, perpendicular to the long axes of trichomes; in old trichomes towards the apical meristematic zones. Trichomes dissociate at heterocytes. Reproduction by hormogonia, which separate from trichomes by necridic cells and by akinetes.

Most of the 13 described species are periphytic, growing among other algae and aquatic plants. Known from the tropics and warmer regions of the temperate zone. Here one species is described from north-eastern Australia Bibliography: Desikachary (1959), Komárek & Watanabe (1998), Komárek (2013), Bohunická et al. (2015).