Anabaena cf. augstumalis Schmidle (1900: 174)

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

Anabaena cf. augstumalis Schmidle (1900: 174) Fig. 36 E–F .

Filaments benthic, epiphytic, solitary, or clustered together into small mats. Trichomes flexuous, with fine, indistinct mucilage, cylindrical, constricted at the cross walls, not attenuated towards the ends. Vegetative cells barrel-shaped to shortly cylindrical, isodiametric, or up to 1.6 × longer than broad, (3.2–) 4–5 μm long × 3–4 μm broad, without aerotopes; apical cells rounded. Heterocytes spherical to oval, intercalary, solitary, (5.0–) 6.0–8.7 μm long × 4.3–6.0 μm broad. Akinetes long cylindrical with rounded ends, solitary or in pairs, remote from or adjacent to heterocytes, 18–28 μm long × 6–10 μm broad.

Specimens examined:—Brown L., North Stradbroke Is.

Other records:— Northern Territory, Thomasson (1986).

Observations:—Uncommon, observed as part of the periphyhton attached to the emergent sedge, Lepironia articulata (Retz.) Domin , in the littoral zone of an acidic perched lake. A. augustumalis is known from similar peaty habitats throughout the temperate zone. Several varieties have been described including forms with smaller and larger cell dimensions. It has been designated cf. here as the Brown L. material observed differs from typical A. augustumalis by its smaller vegetative cell size, being closer in dimensions to A. augustumalis var. longispora Tarnavschi & Mitroiu (1956) .

Figures

FIGURE 36. A–B Anabaena cylindrica; C–D, G–H Anabaena oscillarioides; E–F Anabaena cf. augstumalis. Scale bars = 20 μm