Hapalosiphon welwitschii

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

Hapalosiphon welwitschii West & G.S.West (1897: 242) Fig. 31 A–D .

Thallus caespitose, with filaments densely entangled, blue-green to olive-green in colour. Filaments flexuous, 5.5–9.0 μm wide. Branches short, erect, slightly narrower than the main filament, and narrowed towards the ends. Sheaths thin, colourless. Trichomes cylindrical, clearly constricted at the cross walls, particularly in older filaments. Vegetative cells rounded barrel-shaped, ± isodiametric; in branches cylindrical, up to 2 × longer than wide, 5.0–9.5 (–15) μm long × 5.5–9.0 (–12.0) μm wide. Heterocytes isodiametric to elongated cylindrical 7.5–12.5 μm long × 5.5–9.6 μm wide.

Specimens examined:—Christmas Ck at Stinson Memorial Park.

Other records:— Queensland: McLeod (1975), Entwisle (1994).

Observations:—Growing on granitic rocks in a small shallow coastal stream amongst colonies of Nostoc and Nostochopsis lobatus .

Other species known from Australia: H. baronii West & G.S.West (1895: 85); H. delicatulus West & G.S.West (1902: 203); H. fontinalis, Bowen Ck, Hinchinbrook Is. , Queensland, A.B. Cribb, 1979 (BRI 0700783), Rainbow Ck, Blackdown Tableland, Queensland, A.B. Cribb, 1974 (BRI 0700784), Mimosa Ck, Blackdown Tableland, Queensland, A.B. Cribb, 1974 (BRI 0700785); H. intricatus West & G.S.West (1894: 271), Lake Jennings Fraser Is., Queensland, A.B. Cribb, 1971 (BRI 0700781); H. lutecolus West & G.S West (1897: 241).

MASTIGOCLADUS

Figures

FIGURE 31. A–D Hapalosiphon welwitschia. Scale bars A–B =20 μm, C–D = 50 μm