Maximum likelihood tree based on partial PC-IGS sequences of 107 cyanobacterial strains. Strains from this study are marked in bold. Bootstrap values above 50 are included. The scale bar indicates 10% sequence divergence. L, Lake Langer; M, Lake Melang; S, Lake Scharmützel. +, PSP toxin producer; −, PSP toxin not detected; *, accession number listed in Table 2 (and see Table S1 in the supplemental material).