carrageen Chondrus crispus, one of the red seaweeds. It is found on both sides of the N. Atlantic but associated especially with Ireland, where the Gaelic carrigín, meaning a little rock, provided its most common name and whence comes ‘Irish moss’, one of the numerous alternative names. The beautiful fan-shaped fronds, which are purplish or reddish-green, are important as the source of carrageenan, a substance which has gelling properties similar to those of agar-agar, an Asiatic product of related red seaweeds in the family Gigartinaceae.
