New taxa of Onosma L. (Boraginaceae, Lithospermeae) from Iran

Onosma ligniclada Attar & Mirtadzadini, sp. nov. and O. elymaitica Attar & Mirtadz., sp. nov., originating from Ilam province, display distinct morphological features that differ from their closest known species, O. albo-rosea Fisch. & C.A.Mey., O. iransharii Ghahr. & Attar and O. bilabiata Boiss. & Buhse respectively. This differentiation is marked by variations in habit, corolla color and size, and leaf morphology on sterile shoots and indumentum of leaves.

In contrast, O. farsistanica Attar & Mirtadz., sp. nov. identified in the Quercus L. forests of Fars province (Quercus brantii var. Persica (Jaub. & Spach) Zohary), exhibits notable distinctions from their closely related species, O. bilabiata, particularly in terms of habitat, growth form, tubercle characteristics, calyx and corolla dimensions. Additionally, the manuscript provides photographic documentation, a distribution map, IUCN conservation assessments, and a diagnostic key for these newly identified species.