Commonly known as blue-green alga, nostoc is a cyanobacterium that forms colonies composed of filaments of cells resembling beads covered in a gelatinous coating. It is locally called cushuro, but it is also known as llullucha, yuyucho, murujutu, cusuro, murmuntu, macha-macha, rachapa, shugur, ululuma, ururupsha, ururupa or “egg of the rivers.” Cushuro has an ovoid shape and is greenish-blue in color. It comes in different sizes and can reach up to the size of a ping-pong ball. Cushuro is a wild plant that can be found in lagoons, wetlands, and wet areas from 3600 m of height in Lima, Ancash, Cajamarca, Cusco, Junín, La Libertad, Puno and the Amazon. The communities generally come to collect it in December when the rainy season begins, which is when it usually thrives in small ponds, springs, wetlands and reservoirs of fresh clean water. Cushuro is an indicator of water quality as well as a biological indicator to determine whether it will be a good year of rainfall, which is critical for agriculture in the community. Harvest is an important moment for families, who gather with their children to collect this alga. Children find this activity particularly entertaining. Cushuro has long been used in the frugal diet of Andean communities, eaten fresh, but not raw, in stews or dried. Furthermore, it has recently become a popular ingredient recently discovered by chefs in Lima, who are calling it “the caviar of the Andes.” It is a very versatile food, used to make a variety of dishes, from ceviche to jam and liqueurs. Cushuro is mostly collected for domestic use and a small part can be found for sale in regional markets. It can sometimes be found in the cities of Huaraz, Cusco, Huancayo and Lima, but only in small quantities. As cushuro thrives in clean waters, pollution, solid waste and mining activities near the villages where the lagoons are located the are threatening the existence of this product.