A small, ornamental grass native to the wet, rocky cliffs of Japan's Honshu Island, including the area around Mount Hakone, after which the species is named. It is a slow spreading, deciduous grass which builds into gently cascading hummocks of bright green that are useful as a simple understorey to light shrubs and as a soft edging to paths or steps. Fine, light sprays of lime green flowers appear during June and July, giving a billowing lightness to planted drifts. The clean, minimalist style of this grass makes it a good choice for formal courtyards or in minimalist urban planters and the fresh green foliage gradually acquires rich russet tones as autumn advances.