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:

50 μm 100 μm 150 μm; x 400 : 31 μm 63 μm 94 μm; x 640

Micrasterias brachyptera (Ehrenberg) Meneghini ex Ralfs , cell body 230 μm long, 195 μm wide, isthmus 40 μm wide, x 400, x 640, Komado marsh (or bog), Showa village and Tajima town, Fukushima Pref., Japan, August 22, 2004, by Y. Tsukii
50 μm 100 μm 150 μm; x 400 : 31 μm 63 μm 94 μm; x 640

Micrasterias brachyptera (Ehrenberg) Meneghini ex Ralfs : Cell body large, ellipsoidal, slightly longer than wide; strong constriction at center; semicell consists of 5 parts; deepest indentations between apical and adjacent parts at right- and left-hand; apical part with tree spiny projections at each corner; lateral parts dichotomously branched two times (i.e., with three notches, central one larger than others); each branch with small notches; cell wall covered with many short spines; (187-216)-294 μm long, (160-176)-250 μm wide, constriction 30-(34-42) μm wide (Illustrations of The Japanese Fresh-water Algae, 1977).