“Yatsushiro, Kumamoto Prefecture, which produces 80 percent of igusa reeds, wants its product to be used in tatami mats for the athletes’ village and other places. ‘It’s a chance to convey Japanese culture overseas. Plus, it’s good public relations for Yatsushiro,” said a city official in charge of the matter.’”

Igusa is the plant used to make tatami mats.

http://the-japan-news.com/news/article/0001147822