Staurastrum capitulum Brébisson 1848
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Lauchsee Moor (Austria), Ibmer Moor (Austria)
Phylogenetic tree: Staurastrum capitulum
Diagnosis:
- cells about 1.5 times longer than wide
- length 37–40 µm, width 24–28 µm
- lateral shape cylindrical, apical shape triangular
- shaped of semi-cells inverted bell-shaped
- apices flat
- cell wall with rings of multi-tipped tubercles
- apices with concentric rows of two-pointed tubercles
- each semicell with one axial chloroplast, each with one pyrenoid
So far I have only found Staurastrum capitulum in Ibmer Moor (July 1997) and in Lauchsee Moor (June 2024). Staurastrum capitulum was common at both sites.
Staurastrum capitulum can be easily recognized by its almost cylindrical shape in lateral view. Apically, the cells widen only slightly, which distinguishes the shape from other Staurastrum species. The cell wall is covered with warts, which are arranged in a ring and each have 2-3 short spines. The size of the cells seems to be very limited. The specimens of my population also had a length of 37–39 µm and were thus in the narrow range of 37–40 µm as indicated by Lenzenweger (1997).
Fig. 1 a-d: Staurastrum capitulum. L = 37 µm. Different focal planes of a specimen in lateral view found in June 2024 in the Lauchsee Moor. Obj. 100 X.
Fig. 2: Staurastrum capitulum. L = 38 µm. A second specimen in lateral view found in July 1997 in the Ibmer Moor. Obj. 100 X.