Staurastrum senarium Ralfs, 1848
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Simmelried
Phylogenetic tree: Staurastrum senarium
Diagnosis:
- cells little longer than wide
- semi-cells elongated oval
- lateral sides convex, apices flat
- length 26–33 µm, width 30–37 µm
- apices with two processes with 2-3 spines
- lateral angles of semi-cells with 2–3 spines
- in apical view 3 axis
- each semi-cell with one axial chloroplast with one pyrenoid
So far I have only found 2 specimens of Staurastrum senarium in the Simmelried. I have not been able to find this alga in any of my other sampling sites. Lenzenweger (1997) found Staurastrum senarium in alpine Sphagnum ponds with a pH value of 5.9–6.2.
Staurastrum senarium shows a high variability, which makes identification difficult. The apical and lateral processes can have 2 or 3 spines. There are no further spines or ornamentally arranged tubercles on the central surfaces of the half-cells. The most conspicuous feature are the 2 or 3 spines that arise at the lateral angles of the semi-cells.
Fig. 1 a-d: Staurastrum senarium. L = 37 µm (with processes). Different focal planes of a slightly squashed specimen. Obj. 100 X.