A genus of Gram-negative bacteria, not assigned to any taxonomic family. Cells are rod-shaped, occurring in chains enclosed by a sheath, or as single cells or pairs of cells. Sheaths often contain oxides of iron or manganese. Free cells are motile with one or more flagella. They are aerobic chemo-organotrophs. They are found in various aquatic habitats, especially in slow-moving, unpolluted streams containing iron, etc.
Subjects: Plant Sciences and Forestry.