Defining Characteristics:
- Colony forming? Yes, generally
- Filamentous? Yes
- Sheath always present
- Aerotopes present in planktonic species
- Often express heterocysts
- In colonial form, the heterocysts are centrally arranged
- Akinetes may be present
- Filaments are heteropolar (tapered at the end)
- Could be confused with: Rivularia
Singular filaments
Colonies of filaments
