Genus: Unicellular; variable in shape; a constriction at the center of the cell body;
mostly longer than wide; flattened; each semicell hemispherical, spherical, ellipsoidal,
rectangular, pyramidal or kidney-shaped; no apical indentation
Subgenus [Eucosmarium]: Cell body dorso-ventrally compressed, with strong constriction at the center, transverse section elliptical or diamond-shaped. Section [Quadratiformes]: Cell surface smooth; semicells rectangular (Illustrations of The Japanese Fresh-water Algae, 1977). Species: |
31 μm
63 μm
94 μm; x 640
Cosmarium rectangulare Grunow var. rectangulare (Quadratiformes, Eucosmarium),
cell body 42 μm long, 31 μm wide, L/W=1.6, isthmus 12 μm wide,
x 640, rice field, near Ichinoseki Railroad Station, Ichinoseki city, Iwate Pref., Japan, July 24, 2005 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
