Genus: Cell body short, radiate in shape; apical view of the cell, triangular, polygonal, ellipsoidal or spindle-shaped; zygospores formed outside of mother cells (Illustrations of The Japanese Fresh-water Algae, 1977) Subgenus: lacks arm-like projections (Illustrations of The Japanese Fresh-water Algae, 1977) Species:

31 μm 63 μm 94 μm; x 640

Staurastrum avicula Brébisson in Ralfs var. subarcuatum (Wolle) W. et. G.S. West (or Staurastrum reinschii Roy f. minor Borge ?), cell body about 25 μm long, 25 μm wide (excluding spines), isthmus 9 μm wide, spiny projections at corners about 3 μm long, x 640, Dojo-ike (pond), Norikura highland, Azumi, Matsumoto city (formerly Azumi village), Nagano Pref., Japan, June 8, 2006 by Y. Tsukii
31 μm 63 μm 94 μm; x 640

Images of collecting locality: Dojo-ike (pond), Norikura highland, Azumi, Matsumoto city (formerly Azumi village), Nagano Pref., Japan, June 8, 2006 by Y. Tsukii