Aulosira sp. A

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

Aulosira sp. A . Fig. 43 D–H .

Filaments solitary or mixed loosely in mats with other algae, straight or flexuous, 5.4–7.0 wide. Sheaths fine, firm, colourless, not lamellated. Trichomes cylindrical, constricted at the cross walls, not attenuated towards the apex. Vegetative cells barrel-shaped, isodiametric up to 2 × longer than broad, 6.0–11.0 μm long × 3.6–5.2 μm wide, blue-green in colour. Heterocytes intercalary, solitary, ± spherical to cylindrical, 3.6–5.8 μm wide × 6.0–11.3 (–14.9) μm long. Akinetes solitary or in short series, adjacent to or remote from heterocytes, cylindrical with bluntly rounded ends, up to 2 × longer than broad, 6.3–11.6 μm long × 4.7–6.8 μm wide, with smooth colourless exospore.

Specimens examined:—Palmer R. at Gum Ck.

Observations:—Forming unconsolidated mats on rocky substrates in a tropical river. Akinetes were common, and often in series.

Other species known from Australia: Aulosira sp. , New South Wales, Noble & Happey-Wood (1987).

CRONBERGIA

Figures

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