Genus:
Variable in shape and in size; mostly longer than wide; strong constriction at center;
semicell pyramid-shaped, apically flattened with indentation (or notch, some species
lack this notch); laterally straight or wavy or indented; one chloroplast in each semicell;
one pyrenoid for each chloroplast
(Illustrations of The Japanese Fresh-water Algae, 1977).
Subgenus: Atomum (Apical area slightly depressed) Section: Retusa (Cell body large; granulated dome(s) at the center of each semicell) Species: |
50 μm
100 μm
150 μm; x 400 :
31 μm
63 μm
94 μm; x 640
