Family: Unicellular or Colonial; cell body spherical, with one or more spiny projections;
a single cup-shaped chloroplast with a pyrenoid; asexual reproduction by zoospore or autospore;
sexual reproduction by fertilization between egg and sperm.
Genus: Colonial; cell body with 2 or more spiny hairs (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
Nakayado historical park, Oka, Okabe-cho, Fukaya city (formerly Okabe town), Saitama Pref., Japan, April 15, 2006 by Y. Tsukii