This paper presents a taxonomic contribution to the genus Pyrus L. P. georgica and P. pseudosyriaca are reported from Turkey for the first time. The status of P. pseudosyriaca is discussed and it is treated as a new variety of Pyrus syriaca. Notes on the chorology, morphological descriptions, figures, and taxonomy are provided. Moreover, P. serikensis and P. boissieriana are reduced to synonyms of P. cordata. | Turkish Journal of Botany Research Article Turk J Bot (2015) 39: 841-849 © TÜBİTAK doi: Taxonomic and nomenclatural contributions to Pyrus L. (Rosaceae) from Turkey Zübeyde UĞURLU AYDIN*, Ali Aslan DÖNMEZ Department of Biology, Faculty of Science, Hacettepe University, Beytepe, Ankara, Turkey Received: Accepted/Published Online: Printed: Abstract: This paper presents a taxonomic contribution to the genus Pyrus L. P. georgica and P. pseudosyriaca are reported from Turkey for the first time. The status of P. pseudosyriaca is discussed and it is treated as a new variety of Pyrus syriaca. Notes on the chorology, morphological descriptions, figures, and taxonomy are provided. Moreover, P. serikensis and P. boissieriana are reduced to synonyms of P. cordata. An endemic subspecies, P. elaeagrifolia subsp. kotschyana, is compared with the related species P. elaeagrifolia and it is reassessed at the species level based on morphology and distribution. With these changes, Pyrus is represented by 18 taxa belonging to 12 species in Turkey. Key words: Nomenclature, Pyrus, Rosaceae, taxonomy, Turkey 1. Introduction Pyrus L. belongs to the subtribe Pyrinae of Rosaceae (Potter et al., 2007). The genus, including both pears and apples, was first described by Linnaeus (1753), and the first comprehensive study of the genus was published by Decaisne (1871–1872), with 23 species arranged in six groups. After that, Koehne (1890) described two sections, Pashia Koehne and Achras Koehne. Fedorov (1954) accepted Koehne’s infrageneric classification and he added two new sections, namely Xeropyrenia Fed. and Argyromalon Fed. These two new sections comprised several microspecies and hybrid species from the Caucasus. The new sections are treated as a subsection by Tuz (1972) and Browicz (1972), who included them in Flora of Turkey. Challice and Westwood (1973) also proposed further relationships for