Paronychia manfrediana (Caryophyllaceae) is decribed as a species new to science based on material collected near the Turkish border in northeastern Greece; it is illustrated by a photograph. Although belonging to Paronychia sect. Heterosepalae it bears a strong resemblance to P.macedonica (Paronychia sect. Anoplonychia), differing by its leaves with prominent midvein beneath, the number of stipules (four) at each node and the outer surface of the sepal which is completely glabrous or adpressed-pubescent only in the upper part. In P. macedonica, the leaf midvein is not as conspicuous, there are two stipules at each node and the entire outer surface of the sepal is densely sericeous. The leaves of P. capitata and P. macrosepala, both in sect. Heterosepalae, differ in being strongly scabrid-hirsute and densely sericeous respectively.