Genus: Planktonic; colony of 16, 32 or 64 cells, irregular in shape, without gelatinous sheath;
colony consists of subsets of 4 cells connected by gelatinous filaments extending from the center;
each subset consists of cells of two types, 2 cells located outward, kidney- or heart-shaped, other 2 cells
located inward, cylidrical, both ends rounded; a single chloroplast plate-like in shape, slightly curved, with a pyrenoid
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
Images of collecting locality:
Maimeno-ike (pond), Norikura highland, Azumi, Matsumoto city (formerly Azumi village), Nagano Pref., Japan, June 8, 2006 by Y. Tsukii