Petasites japonicus.

Botanical name: 

Petasites -species contain livertoxic pyrrolizidine alkaloids. Read more here. -Henriette

Petasites japonicus F. Schmidt. Compositae.

Sakhalin Islands. The young, tender petioles of the leaves are said by Penhallow to be largely used by the Japanese of Yeso as a food. The native name is fuki. It is held in high esteem among the Ainos, although devoid of flavor. The plants are cultivated for their succulent petioles.

Sturtevant's Edible Plants of the World, 1919, was edited by U. P. Hedrick.