オオイワカガミ ooiwakagami

葉の表面に光沢があるので、イワカガミ（岩鏡）という名前がついたそうです。その変種で葉が大きいのがオオイワカガミです。

The surface of the leaf is shiny, so the grass was named iwakagami.
The varietas to have big leaves are ooiwakagame.
In Japanese, "oo" means something big, and "iwa" means a rock, and "kagami" means a mirror.