Pleurotaenium truncatum
(Brébisson ex Ralfs) Nägeli, 1849
Most likely ID: n.a.
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Synonym: n.a.
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Sampling location: Schwemm Moor (Austria)
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Phylogenetic tree: Pleurotaenium truncatum
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Diagnosis:Â
- 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.
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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.