Onosma serpentinica (Boraginaceae), a new serpentine endemic species from the South-West Anatolia, Türkiye

Abstract

A new species of Onosma L. (Boraginaceae: Lithospermeae), Onosma serpentinica Yıldırım & Binzet, from Muğla Province, in south-west Anatolia, Türkiye, is described and illustrated. It grows on the ultramafic slopes at Pinus brutia forest clearings near Göcek district of Muğla Province on elevation between 230–290 m a.s.l. Onosma serpentinica is a serpentine endemic belonging to section Onosma subsection Haplotricha (Boiss.) Gürke. The most similar species from Türkiye is O. argentata Hub.-Mor., which is distributed in only two localities from Erzincan province (Eastern Türkiye) and differs from it by the indumentum type, shorter basal and cauline leaves, fewer-flowered cymes, different corolla colour, different corolla indumentum, longer filaments and styles as well as bigger nutlets. Additionally, the geographical distributions and map, an image of the holotype specimen, diagnostic characters, detailed photographs, habitat descriptions, and an identification key for the new species, O. serpentinica, and O. argentata are provided along with a vernacular name and IUCN conservation status for O. serpentinica.