Chondrus crispus.

Botanical name: 

Chondrus crispus Lyngb. Rhodophyceae. Carrageen. Irish Moss. Pearl Moss.

This alga is found on the western coast of Ireland, England and Europe and also on the eastern coast of the United States. It has been used as a food and medicine by the Irish peasants from time immemorial. It is collected for the market and is largely used as a food for invalids under the names carrageen, Irish moss and pearl moss.

Sturtevant's Edible Plants of the World, 1919, was edited by U. P. Hedrick.