Penium polymorphum (Perty) Perty, 1852

Most likely ID: n.a.


Synonym: n.a.


Sampling location: Sima Moor (Austria)


Phylogenetic tree: Penium polymorphum



  • cells cylindrical or ellipsoidial with rounded ends
  • length 35–75 µm
  • cell wall with longitudinal striae, pass into reticulate pattern at apices
  • 1–4 girdle bands
  • two stelloid chloroplasts with longitudinal ribs and one pyrenoid
Penium polymorphum

I found Penium polymorphum in July 2017 in the Sima Moor (Austria). The alga is not present in my local sites.


The cells of Penium polymorphum are cylindric-oval with each one stelloid chloroplast per semi-cell. The cell wall shows a characteristic pattern. In the middle an almost parallel longitudinal striation is visible what pass into a reticulate pattern towards the apices.


Fig. 1 a-b: Penium polymorphum. L = 57 µm. Two focal planes of a specimen found in July 2017 in the sima Moor. Note the longitudinal striation (LS) of the cell wall which pass into a reticulate pattern (RP) towards the apices. Obj. 100 X.