Scytonema coactile Montagne ex Bornet & Flahault (1886: 90)

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

Scytonema coactile Montagne ex Bornet & Flahault (1886: 90) Figs. 74 A–F.

Thallus caespitose, woolly, often forming irregularly spherical colonies 10–15 cm in diameter, dark blue-green to olive-green in colour. Filaments 16–24 μm wide, with geminate false-branching, branches generally the same diameter as the main filament. Sheaths firm, colourless or yellowish, often lamellated. Trichomes cylindrical, ± constricted at the cross walls. Vegetative cells isodiametric or longer or shorter than broad, 3.5–7.5 (–13.5) μm long × 8.0–11.0 (– 13.5) μm wide; cells in the apical regions shorter than broad, 3.8–4.8 μm long × 11–12 μm wide, apical cells rounded. Heterocytes solitary, cylindrical, isodiametric or longer or shorter than broad, 6.4–10.5 (–19) μm long × 9.0–12.0 (–15) μm broad.

Specimens examined:—Blue L., Eighteen Mile Swamp, Naree Budjong Djara Natl Park, North Stradbroke Is.

Observations:—Metaphytic or attached to emergent sedges in the littoral zone of oligotrophic coastal wallum lakes and wetlands.