Maianthemum dilatatum is accepted species in
the family
Asparagaceae
subfamily:
Nolinoideae,
Genus
Maianthemum 
This species is found in Alaska, Aleutian Is., Amur, British Columbia, California, Chita, Idaho, Japan, Kamchatka, Khabarovsk, Korea, Kuril Is., Mongolia, Oregon, Primorye, Sakhalin, Washington, Yukon.