Scytonema sp. A

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

Scytonema sp. A Fig. 80 A–C.

Thallus an expanded rusty brown film, occasionally turfed across the surface. Filaments 17–23 μm wide, with geminate false-branching, branches generally the same diameter as the main filament. Sheaths firm, thickened and lamellated, yellow to yellow-brown in colour. Trichomes cylindrical, ± constricted at the cross walls. Vegetative cells in the main filaments isodiametric or longer than broad, 6.8–14.5 μm long × 7.9–10.5 μm wide; cells in the apical regions shorter than broad, 3.5–6.3 μm long × 11.5–12.5 μm wide, apical cells rounded. Heterocytes solitary, cylindrical, isodiametric or slightly longer than broad, 10.1–11.0 μm long × 8.6–11.5 μm broad.

Specimens examined:—Coomera R. d/s Yarrabilgong Falls, Lamington Natl Park.

Observations:—Forming greenish-brown coloured crustose films on dripping rock walls and granitic bolders adjacent to clear high altitude streams in subtropical SE Queensland.

Other species known from Australia: Queensland: S. flexuosum, Sonder (1880 , 1881), S. hofmannii, Cribb (1976 , 1984, 1986, 1987, 1988), Entwisle (1989, 1990, 1994), May (1970), S. myochrous, McLeod (1975) , Nordstedt (1888), Playfair (1917); Northern Territory: S. stuposum, Nordstedt (1888) , Playfair (1917).

SCYTONEMATOPSIS