You may have had nori — the ubiquitous red seaweed that dries to black or green — wrapped around rice in sushi maki, or as roasted, salted crisps. Its popularity makes it a good gateway to an array of sea veggies.
http://www.npr.org/2012/07/17/156918881/just-add-water-the-miracle-of-seaweed
See on npr.org
