Ahnfeltia

a genus of red algae. Ahnfeltia is a perennial alga with the form of irregularly branched cords 10–20 cm long and 0.5–1 mm thick, of a dark purple or almost black color. It grows on rocks in the upper levels of the coastal belt, mainly in the cold seas of the northern hemisphere. The most widely distributed is A. plicata, from which a high-quality agar is obtained. Many countries, including the USSR, cultivate A. plicata artificially.