Abstract: During a survey of the genus Onosma L. section ProtonosmaPopov subsect. RostellataeRiedl, we examined several populations assigned to Onosma rostellata Lehm. (sensu lato) using morphology and molecular evidence. Our morphological review revealed a hairy corolla outside in all specimens, an anther length equal to the filament length, and nectariferous rings hairy or glabrous, as opposed to the descriptions provided in Flora Iranica and Flora of Turkey. We updated itsdescription which were in contradiction with the character states found on the type specimen. Five new taxa were identified among the specimens identified as O. rostellata to date and described based on molecular data and morphological examination: Onosma khatamsazii Attar, Mirtadzadini & Sotoodeh – a new species from Kermanshah province, O. fareghanensis Attar, Mirtadzadini & Sotoodeh – a new species from the mountainous region of the north of Hormozgan province, and Onosma maharluensis Attar, Mirtadzadini & Sotoodeh – a new species including two subspecies, namely : O. maharluensis Attar, Mirtadzadini & Sotoodeh subsp. maharluensisand O. maharluensis subsp. boyer-ahmadica Attar, Sotoodeh & Mirtadzadini from Iran.
Abstract: Two new species of Cousinia are described from Iran. Cousinia bornmulleriana from the west that can be placed in sect. Haussknechtii based on some key characters such as flower numbers, phyllary numbers and the inflorescence form traits. This species can be also compared with its closest relative C. haussknechtii. and C. karkasensis. The second new species, C. semnanensis, from North East of Iran, belongs to the sect. Stenocephalae for its flower numbers, winged stem, and phyllaries shape, and is compared to C. alexeenkoana and C. glaucopsis as its close relative.