Euastrum Ehrenberg ex Ralfs 1848

Lumbreras, La Rioja, Spain

A Veiga, Galicia, Espaa

A Veiga, Galicia, Espaa

Galende, Castile and Len, Spain

Galende, Castile and Len, Spain

Galende, Castile and Len, Spain

Galende, Castile and Len, Spain

Lumbreras, La Rioja, Spain

Galende, Castile and Len, Spain

Galende, Castile and Len, Spain

S Pedro, Galicia, Spain

Rancho de la Herradura, Andalusia, Spain

Rancho de la Herradura, Andalusia, Spain

El Maillo, Castille and Leon, Spain

Differential interference contrast.

Euastrum agalma.

Euastrum pecten.

Euastrum gemmatum (BREB.) BREB. var. alatum KOSSINSAJA  The cells are appr. 1.5 times longer than wide and.squarely shaped in the center section. Due to an emargination the lateral line of the shape shows two lobes. The vertex lobes are broadened towards the periphery, rounded on the lateral line and slightly concave in the center of the lobe. The cut in the middle of the cell is deep and peripherally widened. In the center of the cell halves there is a clear hump with small verrucae, on both sides of this hump there is a further, flat hump. This area together with the lateral lobes and the vertex lobes are clearly covered with tiny warts.  Length 55 - 60 µm, width 45 - 50 µm.  Occurrence: Not rare also in weakly acidic ponds in the alpine regions up to an altitude of 2000 m  

Euastrum oblongum (GREV.) RALFS ex RALFS The cells are appr. 2 times longer than wide and slenderly elliptical in shape. The cell halves consists of two clearly distinguishable sets of lobes which are weakly concave in the center. The vertex lobes are clearly contrasted, widened wedge-shaped with a cut in the center. The cuts in the middle of the cell are not peripherally widened. There exists a big pore in the middle of the cell halves between the two humps. Further humps are visible at the lateral lobes. The cell wall is covered with densely packed pores.  Length 150 - 170 µm, width 70 - 85 µm. Occurrence: Adaptable alga, ubiquitous 

Euastrum verrucosum EHRENB. var. groenlandicum (LARSEN) WILLI KRIEG So far only two quite inaccurate illustrations of this alga exist: The original illustration of LARSEN (1904) and an illustration of GROENBLAD (1952). The cell halves are rounded off trapezoidal, both the lateral lobes and the vertex lobe drawn weakly into the center turn into one another, separated only by a shallow emargination. At the ends of the lateral lobes there are several short pricks. The central cuts are far opened. The hump near the isthmus range of the cell halves are covered with large warts, the remaining cell wall with concentric rows of small warts.  Length 100 - 105 µm, width 80 - 85 µm. Occurrence: So far only known from Greenland 

Euastrum attenuatum WOLLE var. splendens (F.E.FRITSCH & RICH.) GRÖNBLAD The cells are almost two times longer than wide. The cell halves have three lobes, the lateral lobes are broad and shallowly undulated at the ends. The vertex lobes are widened at the ends and are surrounded with a collar of warts. In the center of each cell half and on both sides of them there are broad swellings. The central cuts open outwards in an acute-angle. .  Dimension: Length 57 – 60 µm, width 33 – 35 µm  Ecology: In shallow, moderate acidic waters of fens and bogs. Occurrence: South America (Anden up to altitude of 3000 m toTierra del Fuego), Africa (Natal, Sudan), firstly recorded for Europe! 

Euastrum attenuatum WOLLE var. splendens (F.E.FRITSCH & RICH.) GRÖNBLAD The cells are almost two times longer than wide. The cell halves have three lobes, the lateral lobes are broad and shallowly undulated at the ends. The vertex lobes are widened at the ends and are surrounded with a collar of warts. In the center of each cell half and on both sides of them there are broad swellings. The central cuts open outwards in an acute-angle. .  Dimension: Length 57 – 60 µm, width 33 – 35 µm  Ecology: In shallow, moderate acidic waters of fens and bogs. Occurrence: South America (Anden up to altitude of 3000 m toTierra del Fuego), Africa (Natal, Sudan), firstly recorded for Europe! 

Euastrum crameri RACIB. The cells are appr. 1.5 times longer than wide and trapezoidal in shape. The cell sides are formed by flat depressions from two distinct waves.The  vertex lobes are clearly separated, strongly broadened towards the ends. They have a central cut with a spine each on the sides. The central cut of the cell is narrow, the cellwall is covered with warts and denticles.  Dimension: Length 60 – 65 µm, width 45 – 50 µm  Ecology: Sporadic in medium acidic waters of fens and moorlands Occurrence: Rather rare, most of the reported finds are in northern areas and higher altitudes. 

 Euastrum crameri RACIB. The cells are appr. 1.5 times longer than wide and trapezoidal in shape. The cell sides are formed by flat depressions from two distinct waves.The vertex lobes are clearly separated, strongly broadened towards the ends. They have a central cut with a spine each on the sides. The central cut of the cell is narrow, the cellwall is covered with warts and denticles.  Dimension: Length 60 – 65 µm, width 45 – 50 µm  Ecology: Sporadic in medium acidic waters of fens and moorlands Occurrence: Rather rare, most of the reported finds are in northern areas and higher altitudes.