Echinophora sibthorpiana

Tarhana herb or Turkish pickling herb, Echinophora sibthorpiana or "Echinophora tenuifolia" L. subsp. "sibthorpiana" (Guss.) Tutin (Turkish "çörtük"), is a herb sometimes used as a flavoring in tarhana and in pickles. It may also improve the fermentation of tarhana. (Deghirmencioghlu 2005)
The primary essential oils it contains are δ-3-carene, methyleugenol, and α-phellandrene. (Özcan 2003)
Some authors indicate that "Hippomarathrum cristatum" is the "tarhana herb".