Genus: Cell body crescent in shape (long, curved, tapered at both ends); cross section rounded;
cell wall smooth or with longitudinal lines, bands on the cell wall in some species;
chloroplast laminae ridged and radially arranged, which makes cross section star-shaped;
pyrenoids aligned or scattered (Illustrations of The Japanese Fresh-water Algae, 1977).
T=terminal; Tv=terminal vacuole
Closterium moniliferum ?!, x 400, x 640, Uruguay Nov. 1999, photo by Yuuji Tsukii
* C. moniliferum (Bory) Ehrenberg var. moniliferum: 170-(235-384)-450 μm long, 28-(36-60)-72 μm wide; L/W = 6-8; cell body slightly curved; both termini broadly rounded; cell wall transparent, smooth; chloroplasts with about 4 ridges of laminae; pyrenoids arranged in a single line (Illustrations of The Japanese Fresh-water Algae, 1977).
C. moniliferum var. concavum Klebs: cell body curved more strongly than var. moniliferum; 187-(300-344)-372 μm long, 30-(39-45)-56 μm wide; cell wall transparent, smooth; chloroplasts with about 4 ridges of laminae; pyrenoids arranged in a single line (Illustrations of The Japanese Fresh-water Algae, 1977).