General appearance of alga? Non-motile microalgae (single cells).
Habitat freshwater; or terrestrial.
Aquatic type? lake; or pond; or bogs; or puddles and ditches.
Free-living or attached? free-living.
Motile? not recorded.
Is mucilage or gelatinous material present? Absent.
Filament: Branching type not recorded.
Filaments in bundles? not recorded.
Filament: Cell arrangement not recorded.
Filament: Filament diameter not recorded.
Cell: Individual cell shape globose or spherical; or ellipsoid; or ovoid.
Cell: Is there a median constriction (isthmus)? Shallow furrow.
Cell: Do the cells bear spines or cellular extensions? Absent.
Cell: How many flagella per cell? Absent.
Cell: Is a red eyespot conspicuous? no.
Cell: Heterocytes absent.
Cell: Akinetes absent.
Cell: Cell length 20–260 µm.
Cell: Cell diameter 7–110 µm.
Cell: How many pyrenoids per plastid? 2–10.
Cell: How many plastids? 1.
Cell: Plastid shape? star-shaped.
Cell: Position of plastid in cell? Axial; or Parietal.
Colony: Are remnants of the mother cell wall present or is the entire mother cell wall persistent? Mother cell wall absent.
Colony: cell arrangement not recorded.
Colony: Shape of colony? not recorded.
Colony: Are cells or groups of cells connected by mucilaginous threads? No.
Colony: Cells in one layer or throughout not recorded.
Capable of forming blooms? Not observed.
Distribution Western Australia; or Northern Territory; or South Australia; or Queensland; or New South Wales; or Victoria; or Tasmania.
Classification: Division Chlorophyta (Green Algae).
Classification: Class Zygnematophyceae.
Classification: Family Desmidaceae.
referred to Cosmarium, Cylindrocystis, Penium and others.
Species and distribution Nine species reported from Australia.
Reference Croasdale & Flint (1988: 33-39), Dingley (2001), Ling et al. (2000:163), Day et al. (1995:77), Entwisle et al. (1999c