This non-registered hosta from Jeff Miller of Land of the Giants Hosta Farm in Wisconsin forms a giant size plant with unruly, rugose blue-green foliage that tends to stay blue throughout the season.

A Google search says, "Tsunami, (Japanese: “harbour wave”) also called seismic sea wave or tidal wave, catastrophic ocean wave, usually caused by a submarine earthquake, an underwater or coastal landslide, or a volcanic eruption."