Agar, also called agar-agar, gelatin-like product made primarily from the red algae Gelidium and Gracilaria (division Rhodophyta).
Agar is isolated from the algae as an amorphous and translucent product, such as powder, flakes, or bricks.
Agar occurs as a complex cell-wall constituent containing the polysaccharide agarose with sulfate and calcium.