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Common in poor quality streams, lowland rivers »
Phormidium

Algal factsheet: Phormidium (Phormidiaceae)

Phormidium, Taieri River
Phormidium, X640

Diagnostic features

Unbranched filaments of short cylindrical cells in a fine sheath. Filament may glide within the sheath. Cells may be at least as long as they are wide (cf. Oscillatoria). End cells often pointed/tapered, with a calyptra (thickened cap) on the terminal cell. Tapering may extend several cells from the end. Heterocytes absent. Organelles absent from the cells, but granules/vesicles common. Forms mats that may be dark brown, green, purple or blue-green.

Typical habitats

Streams and rivers of all sorts of water quality

Notes

Potentially toxic

Classification

Kingdom	Bacteria
Phylum	Cyanobacteria
Class	Cyanophyceae
Order	Oscillatoriales
Family	Phormidiaceae
Common name	Cyanobacteria