Staurastrum spongiosum var. perbifidum
West, 1892
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Paradieswiesen (Austria)
Phylogenetic tree: Staurastrum spongiosum var. perbifidum
Diagnosis:
- cells about as wide as long, semi-cells broadly oval
- lateral sides convex
- length 60–65 µm, width 55–63 µm
- semi-cells covered with multi-tipped warts in concentric rows
- number and arrangement of warts variable
- in apical view 3 axis, rarely 4 axis
- each semi-cell with one axial chloroplast with one pyrenoid
I have so far only found Staurastrum spongiosum var. perbifidum once in June 2024 in the Paradieswiesen in Austria.
The main characteristic of Staurastrum spongiosum var. perbifidum are the multi-tipped warts covering the half-cells. Their arrangement is subject to a certain variability. This also applies to the number of axes in apical view. The cell symmetry is usually triaxial. However, 4-axis variants also occur. This desmid alga is very adaptable and has been found up to an altitude of 2500 meters.
Fig. 1 a-d: Staurastrum spongiosum var. perbifidum. L = 55 µm. Different focal planes of a slightly squashed specimen. PY = pyrenoid. Obj. 100 X.