ユリ科ワスレグサ属の多年草で、学名は Hemerocallis dumortieri var. esculenta。英名はありません。
The "Nikko-kisuge" (Hemerocallis dumortieri var. esculenta) belongs to Liliaceae (the Lily family). It is a perennial herb that is distributed northward from Chubu district of Honshu to Hokkaido in Japan, as well as the Kuril Islands and Sakhalin. This herb grows in montane to upland grasslands and can reach 60-80 cm in height. The yellow flowers appear on the flowering stalks from June to August. They last one day. The Japanese name comes from the fact that its leaves resemble the "Kasa-suge" (Carex dispalata) that makes the traditional Japanese hat, and that it is often found near Nikko.