Calothrix brevissima

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

Calothrix brevissima G.S.West (1907: 180) Fig. 57 A–C.

Filaments epiphytic, single or in small groups, short, up to 100 μm long, (5–) 6.0–7.5 μm wide, not or slightly tapered towards the ends. Sheath thin, firm, narrow, cylindrical or slightly tapered, colourless. Trichomes short, up to 110 μm long, cylindrical, straight or sometimes flexuous, slightly narrowed towards the ends, not or slightly constricted at the cross walls, blue-green to olive in colour, without terminal hairs. Vegetative cells mostly isodiametric to shorter than wide, shortly cylindrical to barrel-shaped, 3.5–5.5 μm wide; apical cells rounded. Heterocytes basal, solitary, hemispherical to spherical, 5.5–6.5 μm wide. Akinetes not observed.

Specimens observed:—Einasleigh R. at Talaroo.

Other records:— Queensland: SE Queensland, McLeod (1975).

Observations:—Epiphytic on filaments of Scytonema growing amongst aquatic macrophytes in a riverine waterhole. Compare with species from the genus Microchaete .