Pleurotaenium truncatum
(Brébisson ex Ralfs) Nägeli, 1849
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Schwemm Moor (Austria)
Phylogenetic tree: Pleurotaenium truncatum
Diagnosis:
- semi-cells slightly swollen, slightly tapered to the apices
- length 350–600 µm, width 50–75 µm
- basal inflation absent
- apices smooth, flatly rounded, with ring of 13–15 warts
- chloroplasts irregularly torn, ribbon-like, with scattered pyrenoids
- cell wall smooth, very delicate punctate
I have only found a few specimens of Pleurotaenium truncatum in the Schwemm Moor in Austria. Lenzenweger (1996) describes it as adaptable and widespread.
The main characteristics of Pleurotaenium truncatum are the lack of basal thickening of the semi-cells and the ring of small warts around the flat apices (s. fig. 3). The similar species Pleurotaenium trabecula has slight basal thickening and lacks the ring-shaped warts. In addition, the cells of Pleurotaenium trabecula are often slightly curved.
Fig. 1 a-b: Pleurotaenium truncatum. L = 448 µm. Two focal planes of a specimen in DIC. Obj. 40 X.
Fig. 2 a-b: Pleurotaenium truncatum. L = 448 µm. The same specimen as shwon in fig. 1 a-b in brightfield illumination. Obj. 40 X.
Fig. 3: Pleurotaenium truncatum. L = 448 µm. A section of fig. 2 a. One of the warts, which are arranged in a ring around the apices, is in the focal plane (arrow). Obj. 40 X.