Genus:
Cell body flat, large, variable in shape, longer than wide; strong constriction at center;
each semicell with several notches; cell wall with many short spines
(Illustrations of The Japanese Fresh-water Algae, 1977).
Species:
Micrasterias apiculata (Ehrenberg) Meneghini ex Ralfs
cell body 254 μm long, 200 μm wide (excluding spines), L/W=1.3, isthmus 56 μm wide,
x 200, x 400, x 640, Midori-no-ike (pond), Togakushi Forest Botanical Garden, Togakushi highland, Shinano town, Nagano Pref., Japan, June 12, 2005 by Y. Tsukii
50 μm
100 μm
150 μm; x 400 :
31 μm
63 μm
94 μm; x 640
x 640