Rhagadiolus is a small genus of annual herbs in the tribe Cichorieae, within the daisy family Asteraceae (order Asterales). The genus is native to the Mediterranean basin, encompassing southern Europe, northern Africa, and the Middle East. Plants in this genus produce the characteristic composite flower heads typical of the Asteraceae family, with all florets being ray florets (ligulate heads), as is common in tribe Cichorieae.
The genus presently contains two accepted species. Rhagadiolus edulis Gaertn. ranges from Portugal and Morocco eastward to Iran, while Rhagadiolus stellatus (L.) Gaertn. extends from Britain and the Canary Islands through the Mediterranean to the Caucasus, and has been naturalized in California in Sonoma and Napa Counties. Historically, a number of species were placed within Rhagadiolus that are now assigned to other genera including Crepis, Garhadiolus, Hedypnois, Hyoseris, Koelpinia, and Leontodon.
Distribution
Rhagadiolus is native to the Mediterranean region, spanning southern Europe, northern Africa, and the Middle East. R. edulis ranges from Portugal and Morocco east to Iran; R. stellatus extends from Britain and the Canary Islands through the Mediterranean basin to the Caucasus, and has become naturalized in California (Sonoma and Napa Counties).
Taxonomy Notes
The genus has undergone significant revision: numerous species formerly placed in Rhagadiolus have been transferred to other genera, including Crepis, Garhadiolus, Hedypnois, Hyoseris, Koelpinia, and Leontodon. GBIF recognizes the genus as accepted within family Asteraceae, order Asterales, but records only one descendant, reflecting current narrow circumscription of the genus.
