A red-seaweed genus found on rocky shores in many temperate parts of the world. It supplies carrageenans commercially, used for thickeners, gels, and stabilizers in the food industry; some species are now cultivated commercially to secure supply. Their harvest links marine farming directly to the texture of dairy desserts, processed meats, pet foods, and bottled beverages — a reminder that many everyday food textures begin life on a wave-washed rock. Sustainable harvesting practices protect the coastal ecosystems that produce them, and cultivation trials continue to expand farmed supply.