Nostoc linckia Bornet ex Bornet & Flahault (1886: 193)

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

Nostoc linckia Bornet ex Bornet & Flahault (1886: 193) Fig. 49 A–D.

Thallus macroscopic, fine, thin, mucilaginous, blue-green to blackish-green in colour, initially attached to the substrate, later free floating as irregularly clusters. Filaments flexuous, densely entangled, constricted at the cross walls. Vegetative cells sub-globose to barrel-shaped, 3.0–5.8 μm in diameter. Heterocytes sub-spherical, 4.5–6.5 μm in diameter. Akinetes globose, 6–9 μm long × 4.5–7.0 μm broad, with smooth, colourless to brownish outer cell wall.

Specimens examined:—Fitzroy R., Endeavour R. at Jensen’s Crossing, Einasleigh R. at Talaroo.

Other records:— Queensland: Reynolds Ck, A.B. Cribb, 1949 (BRI 0701421), Burnett Ck, Mt Barlow, A.B. Cribb, 1973 (BRI 0701422), Bailey (1895), Bailey (1913), SE Queensland, McLeod (1975); New South Wales: Barwon Valley Park, Belmont, Geelong, S. Skinner, 2003 (NSW 627347), Victoria: Entwisle (1994), Hardy (1906).

Observations:—Growing in shallow littoral areas and backwaters of streams and rivers. Often detaches from the substrate and becomes free floating in the water column. Australian strains have been associated with the production of the cyanotoxin microcystin ( Gaget et al. 2017).