Euastrum neosinuosum
O.V. Anissimova & Guiry, 2021
Most likely ID: n.a.
Synonym: Euastrum sinuosum, Euastrum circulare var. falaisense
Sampling location: Schwemm Moor (Austria)
Phylogenetic tree: Euastrum neosinuosum
Diagnosis:
- semi-cells almost trapezoidal with rounded corders
- length 70–85 µm, width 35–45 µm
- apical lobe separated by deep incision
- two lateral lobes and two basal lobes per semi-cell
- semi-cells with each 5 protuberances
- one central pore in each semi-cell
- protuberances covered with inconspicuous warts
- deep, linear sinus
So far, I have only found Euastrum neosinuosum in the Schwemm Moor in Austria. There were a large number of specimens in the samples.
Euastrum neosinuosum can be identified by its trapezoidal semi-cells with lateral, hump-shaped lobes. The apical lobe is divided by a deep incision, which is closed at the top. The cell wall is significantly thickened at the projections and covered with fine warts. Each semi-cell has a total of 5 protuberances and a central pore (s. fig. 1 a-c).
The similar species Euastrum aboense is slightly smaller (max. 60 µm), has less pronounced lateral lobes, and has no warts on the surface. In addition, Euastrum aboense has 6 more pores between the protuberances of the semi-cells in addition to the central pore.
Fig. 1 a-c: Euastrum neosinuosum. L = 85 µm. Three focal planes of a specimen found in the Schwemm Moor. Each semi-cell has a central pore (PO) and 5 protuberances (1–5). Obj. 100 X.
Fig. 2 a-c: Euastrum neosinuosum. L = 85 µm. The sames specimen as shown in fig. 1 a-c in brightfield illumination. Obj. 100 X.