Species:
Cell body cylindrical, medium in size, both ends broadly rounded,
(56-65)-80 μm long, 20-31 μm wide,
L/W=2-2.5; cell wall thick, densely dotted, transparent or brownish in color
(Illustrations of The Japanese Fresh-water Algae, 1977).
Penium rufescens Cleve ?,
cell body 52 μm long, 24 μm wide, L/W=2.2,
x 640, No.4, Tanohara marsh, Shiga highland, Yamanouchi town, Nagano Pref., Japan, June 17, 2007 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
Images of collecting locality:
No.4, Tanohara marsh, Shiga highland, Yamanouchi town, Nagano Pref., Japan, June 17, 2007 by Y. Tsukii