Kappaphycus alvarezii as semirefined carrageenan. "K. alvarezii" is affected by ice-ice, a disease that severely reduces its yield. This alga is an introduced species and a noxious aquatic weed in Hawaii. Kappaphycus alvarezii Kappaphycus alvarezii, the elkhorn sea moss, is a species of red algae. It is one of the most important commercial sources of carrageenans, a family of gel-forming, viscosifying polysaccharides. Farming methods affect the character of the carrageenan that can be extracted from the seaweed. This alga grows to two meters long and is green or yellow in color. It is very fast-growing, known to double its biomass in 15
Purple Ages, those who dyed blue fabric and red fabric were members of different guilds, and were forbidden to dye any other colors than those of their own guild. Most purple fabric was made by the dyers who worked with red, and who used dye from madder or cochineal, so Medieval violet colors were inclined toward red. Orcein, or "purple moss", was another common purple dye. It was known to the ancient Greeks and Hebrews, and was made from a Mediterranean lichen called archil or dyer's moss (Roccella tinctoria), combined with an ammoniac, usually urine. Orcein began to achieve popularity again