Somewhat surprised? Yes, Fennel…The bulb, foliage, and seeds of the fennel plant are widely used with culinary and medicinal uses, and, along with the similar-tasting anise is one of the primary ingredients of Absinthe.
Absinthe achieved it’s great great popularity in the late 19th and early 20th century. Artists and intellectuals of those times were the ones especially devoted to Absinthe. Many great works of contemporary art owe their existence to the mystery of the Green Fairy. Great names like Baudelaire, Manet, Verlaine, Rimbaud, Oscar Wilde, Degas, Toulouse-Lautrec, van Gogh, Gauguin and Picasso are found among these early adepts of Absinthe.
Source: Alandia World of Absinthe.