A new species and a synonym in Centaurea sect. Microlophus (Asteraceae, Cardueae–Centaureinae) from the Khuzestan Province, southwestern Iran

A new species, Centaurea baghmalekensis Negaresh (Asteraceae) in C. sect. Microlophus (Cass.) DC., is described and illustrated from the Khuzestan Province, southwestern Iran. The new species is morphologically most similar to Centaurea pabotii Wagenitz, a recently described species from the Khuzestan Province. However, it clearly differs from the latter by having a perennial habit, stems several and branched from the middle to above, branches overtopping relative main axis, undivided leaves with arachnoid indumentum, smaller involucres, median phyllaries ending in a minute mucro usually 0.5–1.0 mm long, yellow flowers, and shorter achenes with loosely hairy indumentum. The ecology, habitat, and conservation status of the new species are also described. The geographic distribution of the new species and closely related species is presented and mapped. In addition, the name Centaurea masjedsoleymanensis Ranjbar and Askari is treated as a taxonomic synonym of C. pabotii . Finally, a taxonomic key to species of C. sect. Microlophus in the Khuzestan Province is provided.