Eucheuma denticulatum
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. Cultivation of "Eucheuma" started in the Philippines in the early 1970s and has since been introduced to many other locations with varying results. There are different methods of cultivating "E. denticulatum". One of the more common ones  is the off-bottom "tie-tie"-method, with the setup being two stakes driven into the sediment with a rope between them. Pieces of the seaweed are then tied to the rope at regular intervals and allowed to grow for 6 weeks, after which it is harvested and dried. 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.