Eryngium maritimum.

Botanical name: 

Eryngium maritimum Linn. Umbelliferae. Sea Eryngo. Sea Holly. Sea-Holm.

Asia Minor and the seashores along the Mediterranean and Atlantic as far as Denmark. The young, tender shoots, when blanched, may be eaten like asparagus. The roots are candied and sold as candied eryngo. When boiled or roasted, the roots resemble chestnuts and are palatable and nutritious.

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