Euphorbia akmanii, a new species of Euphorbiaceae (sect. Patellares) from Turkey (Osmaniye) is described on the basis of morphological characters. The species was found in the north-west part of the Amanus Mountains growing in open deciduous forests. It can be distinguished from E. erubescens by its longer stems, pubescent leaves and fruits, unicellular hairs, petiolate-subsessile second year cauline leaves and laciniate cyathial gland appendages. Diagnostic characters, a full description, and detailed illustrations are presented. These diagnostic characters and other observations concerning the new species are presented and compared with those from species of the sect. Patellares occurring in Turkey. The new species is the only one in sect. Patellares having laciniate gland appendages and unicellular hairs. Micromorphological structures of fruit and seed surfaces of E. akmanii and E. erubescens were examined by SEM. The geographical distribution of species of sect. Patellares in Turkey is mapped. An IUCN redlist category is proposed, and observations on the habitat are provided.