Irish moss is a red marine algae known botanically as Chondrus crispus, a member of the Gigartinaceae family found along the rocky coasts of Europe and North America. It forms flat, branching fronds, and the whole seaweed, or thallus, is the part traditionally collected and used.
In traditional practice, Irish moss has been simmered into gels, drinks, and broths and valued for its soothing, mucilaginous texture. It has also long been used as a household thickener in food and herbal preparations.
Irish moss is sometimes confused with other sea moss products sold commercially, but the classic North Atlantic herb is Chondrus crispus.

