Heliotropium samoliflorum subsp. erzurumicum (Boraginaceae), a new subspecies from Turkey

Heliotropium samoliflorum was formerly regarded as an endemic species of Iran until the collection of the species from Erzurum (Turkey). Due to the presence of clavate intercalary lobes of corolla and hairy indumentum of the nutlets, the Turkish material is described as H. samoliflorum subsp. erzurumicum Donmez subsp. nova and illustrated. Description of H. samoliflorum is given with observed new characters. Identification key to the species of Heliotropium in Turkey is reorganised by inserting two species, based on H. samoliflorum as well as on other species recorded by previous authors.