The draft genome sequences of five species of named phototrophic heliobacteria in the order Clostridiales were determined. Whole genome phylogenetic and average nucleotide identity comparison for the heliobacteria suggests that Heliobacterium chlorum and Heliobacillus mobilis are closely related to one another and belong to the same genus. The three species Heliobacterium modesticaldum , Heliobacterium undosum and Heliobacterium gestii all belong in the same genus, but are more divergent from Hbt. chlorum and belong in a separate genus, which we suggest to be called Heliomicrobium. Heliorestis convoluta is properly recognized to be in the same genus as Heliorestis acidaminivorans. Heliophilum fasciatum is clearly unlike any other and rightfully belongs in a separate genus.