Scytonema obscurum Hansgirg ex Forti

In clear stagnant waters, rarely (secondarily) on wet soils near the water, now very rare (Komárek, J. 2013. Cyanoprokaryota, 3. Teil: Heterocytous genera. In: Büdel, B., Gärtner, G., Krienitz, L. & Schlager, M. (eds). Süsswasserflora von Mitteleuropa 19/3. Springer, Berlin Heidelberg, 1133 pp.)