| Colony morphology |
Densely gelatinous filaments, light green to deep green |
Diffuse, light colored, spreading colony, dull grayish blue-green |
| Filament morphology |
Flexuous, bent, slightly coiled |
Tapering |
| Filament structure |
Solitary, polar, non-tapering |
Heteropolar, tapering, strongly constricted at crosswalls |
| Branching |
Branched |
Branched |
| Sheath |
Present on some filaments, colorless |
Thin, barely visible, colorless |
| Cross-walls |
Present |
Present |
| Vegetative cell shape |
Cylindrical to barrel shaped |
Isometric, longer than wide near trichome apex |
| Vegetative cell dimensions (µm) |
5.4×4.2-10.1 |
3.8-4 × 2.5-5.5 |
| Vegetative cell granulation |
Mostly granular |
Homogenous to sparsely granular |
| Heterocyte shape |
Ellipsoidal to cylindrical |
Solitary, basal, hemispherical |
| Heterocyte dimensions (µm) |
4-4.5× 5.1 |
2.5-4.4 ×3.6-4.4 |
| Akinete morphology |
Spherical, very rare, solitary, in the middle of filaments or free from filaments |
Forming in series in basal portion of trichome, homogenous to coarsely granular |
| Akinete dimensions (µm) |
5.1-7.6×6.5-7.1 |
3.3-7.5 |
| Akinete granulation |
Homogenous to coarsely granular |
Homogenous to coarsely granular |
| Hormogonia |
Present |
Not present |
| Necridia |
Occasionally found |
Not present |
| Habitat |
Lithophytic on stones in freshwater pond, northern Iran |
Lithophytic on cave wall, Kauai, Hawaii |