Eucheuma denticulatum is a species of red algae and one of the primary sources of iota carrageenan. It exists naturally in the Philippines, tropical Asia, and the western Pacific, but for the commercial extraction of carrageenan it is usually cultivated. The species is commonly known as E. spinosum when cultivated and can be found in different colours: brown, green and red. The species was originally described in 1768 as Fucus denticulatus by Nicolaas Laurens Burman and in 1917 transferred to the genus Eucheuma by F.S. Collins and A.B. Hervey.