Irish moss, (Chondrus crispus), also called carrageen, species of red algae (family Gigartinaceae) that grows abundantly along the rocky parts of the Atlantic coast of the British Isles, continental Europe, and North America. Irish moss possesses 15 essential elements that create human body such as calcium, sulphur, iodine and potassium along with Vitamins A, E, D, F and K.