Cylindrospermum stagnale (Kützing) ex Bornet & Flahault (1888: 250)

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

Cylindrospermum stagnale (Kützing) ex Bornet & Flahault (1888: 250) Fig. 43 I–L .

Thallus mucilaginous, flat, amorphous, blue-green to greyish green in colour. Trichomes flexuous, constricted at the cross walls. Vegetative cells isodiametric or up to 2 × longer than wide, 4.5–7.0 μm long × 3.5–5.0 μm broad, without aerotopes. Heterocytes elongate conical or ovoid, 7–16 μm long × 5–8 μm broad, adjacent to akinetes. Akinetes cylindrical to broadly oval, rounded at the ends, 20–45 μm long × 10–15 μm broad, with smooth reddish-brown exospore.

Specimens examined:—Babinda Ck at the Boulders, Soda Springs, Yabba Ck at Stirling’s Crossing.

Other records:— Queensland: Mt Crosby, Queensland, A.B. Cribb, 1963 (BRI 0700614); New South Wales: Irrigation channel, Griffith-Leeton Rd, S. Skinner, 2001 (NSW 627239), Deer Park R., Waterfall Way, Dorrigo-Ebor Rd, S. Skinner, 2000 (NSW 481099), Zoom Ck, N of Walcha, S. Skinner, 2000 (NSW 446041).

Observations:—Cosmopolitan species, growing amongst other algae, and attached to aquatic vegetation and woody debris (Komárek 2013); in northern Australia, more commonly encountered in cooler high-altitude streams.

Figures

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