Nostoc verrucosum Vaucher ex Bornet & Flahault (1886: 216)

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

Nostoc verrucosum Vaucher ex Bornet & Flahault (1886: 216) Figs. 51 A–D , 52 A–B , 54 E .

Colonies gelatinous, initially irregularly spherical to ellipsoidal, when mature, folded, lobate and hollow, 3–10 cm in diameter, olive-green to brownish in colour, filaments densely entangled. Trichomes flexuous, ± indistinct sheaths, sometimes obvious around individual filaments in mature colonies, constricted at the cross walls. Vegetative cells shortly barrel-shaped, isodiametric or slightly shorter than wide, 2.5–3.7 μm long × 3.2–4.8 μm wide, dull blue-green in colour. Heterocytes sub-spherical, 4.2–6.2 μm in diameter. Akinetes sub-spherical, single or in series, 3.8–5.2 μm in diameter, with smooth colourless cell wall.

Specimens examined:—Cattle Ck at Gargett, Christmas Ck at Stinson Memorial Park, Isaac R. at Yatton.

Observations:—Forming conspicuous macroscopic colonies on granitic rocks in clear, flowing streams, frequently along with Nostochopsis lobatus . Mature colonies may elongate and break away from the surface, becoming free floating in the water column. Considered cosmopolitan (Komárek 2013).

Other records:— Queensland: D’Aguilar Range, Northbrook Ck, Mt Glorious-Dundas Rd, Entwisle , 1993 ( MEL) , New South Wales: Woodenbong Ck, Old Koreelah, Mt Barney, Entwisle , 1997 ( MEL) , Sherard Falls, Dorrigo Natl Park, Entwisle , 1997 ( MEL) , Junction of Peel R. and Wombramurra Ck, Entwisle , 1977 ( NSW A3127 ) , Peel R., May 1977, ( NSW A3128 ) , Peel R., May, 1977 ( NSW A3129 ) ; Krui R., Collaroy, Entwisle , 1997 ( MEL) , Ashfield, S. Skinner , 2000 ( NSW) , Murray’s ricefield, Griffith, May 1978 ( NSW A3122 ) .

Figures

FIGURE 51. A–D Nostoc verrucosum. Scale bars A–B = 20 μm, C–D = 50 μm

FIGURE 52. A–B Colonies of Nostoc verrucosum growing on granitic rocks.

FIGURE 54. A–C Wollea ambigua; D Colonies of Wollea saccata; Colonies of Nostoc verrucosum. Scale bars = 20 μm