Aulosira laxa Kirchner ex Bornet & Flahault (1886: 256)

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

Aulosira laxa Kirchner ex Bornet & Flahault (1886: 256) Fig. 43 A–C .

Filaments solitary or loosely entangled in mats, straight or flexuous, 8–10 (–11.5) wide. Sheaths fine, firm, colourless, sometimes diffluent, not lamellated. Trichomes ± cylindrical, constricted at the cross walls, not attenuated towards the apex. Vegetative cells barrel-shaped, shorter than wide, blue-green in colour, (3.5–) 4.2–5.3 μm long × 7.0–8.2 μm wide. Heterocytes intercalary, solitary, ± spherical to cylindrical, 7.0–8.5 μm wide. Akinetes solitary or in short series, cylindrical, remote or adjacent to the heterocytes, 15–25 μm long × 5–8 μm wide, with smooth colourless exospore.

Specimens examined:—Toogoom Lagoon, Northshore.

Observations:—Growing amongst other algae and submerged aquatic plants in a shallow eutrophic urban lagoon.

Figures

FIGURE 43. A–C Aulosira laxa; D–H Aulosira sp. A; I–L Cylindrospermum stagnale. Scale bars = 20 μm