Nori

Nori is a dried edible seaweed used in Japanese cuisine, usually made from species of the red algae genus Pyropia, including P. yezoensis and P. tenera. It has a strong and distinctive flavor, and is generally made into flat sheets and used to wrap rolls of sushi or onigiri (rice balls). The finished dried sheets are made by a shredding and rack-drying process that resembles papermaking. They are sold in packs in grocery stores for culinary purposes. Since nori sheets easily absorb water from the air and degrade, a desiccant is needed when storing nori for any significant time. Originally, the term nori was generic and referred to seaweeds, including hijiki. One of the earliest descriptions of nori is dated to around the eighth century. In the Taihō Code that was enacted in 701, nori already was included in the form of taxation. Local people were described as drying nori in Hitachi Province fudoki (721–721), and harvesting of nori was mentioned in Izumo Province fudoki (713–733), showing that nori was used as food from ancient times. In Utsubo Monogatari, written around 987, nori was recognized as a common food. Nori had been consumed as paste form until the sheet form (ita-nori 板海苔) was invented in Asakusa, Tokyo, around 1750 in the Edo period through the method of Japanese paper-making.

Source: Wikipedia