eng Balkan flora, sect. Acrocentron, new species, taxonomy, chromosome number 2024 info:eu-repo/semantics/article Centaurea ozrenii (Asteraceae) ‒ a new local endemic and extremely rare species from Mt. Ozren near Sjenica in Serbia https://unilib.phaidrabg.rs/o:5909 doi:10.2298/BOTSERB2402263B Buzurović, Uroš Dragićević, Snežana Niketić, Marjan Tomović, Gordana Jakovljević, Ksenija Vuksanović, Snežana Lazarević, Maja Abstract: A new species of Centaurea sect. Acrocentron (Asteraceae) was found on the Ozren mountain in southwestern Serbia near Sjenica and named as Centaurea ozrenii. It inhabits xerophilous and steppe-like habitats, on ultramafic geological substrate. Morphologically, it is close to C. calocephala, C. chrysolepis, C. orientalis, C. murbeckii, C. kotschyana and the recently described C. zlatiborensis. The most distinctive morphological features of the new species are undivided to simply pinnatisect (non lyrate) subglabrous leaves, with linear segments, upper leaves with an aristate apex and cream coloured to pale yellow florets of which the outer are much longer than the inner ones. The phyllaries are intermediate in relation to C. calocephala and C. kotschyana. The chromosome number of the new species is 2n = 22. Thorough field investigations confirmed the presence of C. ozrenii only at this localized site on Mt. Ozren with a population of 13 clusters of individuals with 23–52 flowering stems in an area of about 50 m2. Applying the IUCN Red List categories and criteria to the available data categorised C. ozrenii as a Critically Endangered (CR) species. application/pdf 1602570 bytes Botanica Serbica startpage: 236 endpage: 271 All rights reserved