Fischerella (Bornet & Flahault) Gomont (1895:49)

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

Fischerella (Bornet & Flahault) Gomont (1895:49)

Type: F. thermalis Gomont (1895: 52)

Filamentous, thallose; thallus prostrate, felt-like, rarely in compact mats, composed of creeping, uni- or multiseriate filaments forming erect uniseriate branches. Creeping trichomes usually moniliform, enveloped by thick, waved, sometimes slightly lamellated and coloured sheaths; vegetative cells usually barrel-shaped, sometimes enveloped by their own gelatinous sheaths; erect, T-type branching developing usually unilaterally after lengthwise cell division in basal trichomes, usually cylindrical, with cylindrical and often elongated cells and thin, mainly colourless sheaths. Vegetative cells often with slightly granular contents. Heterocytes intercalary, sub-spherical in basal trichomes, cylindrical in branches. Akinetes develop occasionally and irregularly in basal trichomes. Reproduction by uniseriate hormogonia which separate from the ends of branches; typically, hormogonia are morphologically distinct from the main branches, with aerotopes.

A worldwide genus with 19 species that are currently accepted taxonomically; most are known from moist soils, or growing subaerophytically on walls and terrestrial vegetation, few are known from aquatic habitats.

Two species are known from Australian freshwaters. Here one species is described from north-eastern Australia. Bibliography: Gugger & Hoffmann (2004), Fiore et al. (2009), Komárek et al. (2014).