Micrasterias denticulata var. angulosa
(Hantzsch) West & G.S. West, 1902
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Jackl Moor (Austria), Ibmer Moor (Austria)
Phylogenetic tree: Micrasterias denticulata var. angulosa
Diagnosis:
- cells slightly elongated, lateral margings concave
- length 180–280 µm
- linear deep sinus
- semi-cells 5 lobed
- lobes with slight indentation and smoth edges
- polar lobe wedge-shaped, sometimes protruding
- cell surface smooth, with fine pores
I found Micrasterias denticulata var. angulosa in June 1995 in the Jackl Moor (Austria) and in the Ibmer Moor (Austria). The specimen shown below is from the Jackl Moor. This form differs from the basic species Micrasterias denticulata by the slightly concave indentations of the lateral margins (s. fig. 1 a). I have not yet found Microsterias denticulata var. angulosa in my sampling sites on Lake Constance.
Fig. 1 a-b: Micrasteria denticulata var. angulosa. L = 284 µm. A specimen in DIC (a) and in dark field illumination (b). Note the slight concave form of the lateral margins (arrowheads). Obj. 20 X.