Mercurialis annua.

Botanical name: 

Mercurialis annua Linn. Euphorbiaceae. Annual Mercury.

Europe and north Africa and occasionally found spontaneously growing in the United States. Annual mercury, says Johnson, is eaten in Germany, the poisonous principle which it contains in small quantity being dissipated in boiling.

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