Phytotaxa 340 (1): 048–054 http://www.mapress.com/j/pt/ Copyright © 2018 Magnolia Press Article PHYTOTAXA ISSN 1179-3155 (print edition) ISSN 1179-3163 (online edition) 48 Accepted by Manuel B. Crespo: 21 Dec. 2017; published: 21 Feb. 2018 https://doi.org/10.11646/phytotaxa.340.1.2 Acantholimon ibrahimii (Plumbaginaceae), a new species of A. section Staticopsis from the Mediterranean part of Turkey GALIP AKAYDIN Department of Biology Education, Hacettepe University, 06800 Beytepe, Ankara, Turkey; e-mail: agalip@hacettepe.edu.tr Abstract A new species, Acantholimon ibrahimii Akaydın, is described, illustrated and discussed in comparison with its close relative A. davisii. The new species is distinguished from the latter species mainly by the generative organs (namely the inflorescence types and petals colour), habitat type and ecological behaviour. Data are also reported on the conservation status of A. ibra- himii, which is suggested to be labelled as EN according to the IUCN categories. Furthermore, a revised key to the Turkish Acantholimon species of A. sect. Staticopsis with spike laxly distichous and scape much longer than leaves is presented. Key words: Acantholimon, A. sect. Staticopsis, conservation, endemism, Staticoideae, taxonomy. Introduction The genus Acantholimon was first described by Boissier (1846: 69). It includes perennial, densely or laxly pulvinate, cushions forming thorny subshrubs, and is currently accepted to contain about 200 taxa, mainly distributed from southeastern Europe to Central Asia (Kubitzki 1993). The main distribution centres of the genus are located in the eastern Mediterranean and the Irano-Turanian regions (Bokhari 1970, Doğan & Akaydın 2011), in which many endemics occur. Its taxa have considerable ecological, economic and ornamental importance with long-lasting and nicely coloured flowers (Doğan & Akaydın 2004). Bunge (1872) prepared the first revisionary study of Acantholimon in which 83 species classified under 7 sections were recognised and some specimens from Turkey were also included. Boissier (1879) in his Flora Orientalis recognized 74 species in the area and classified them under the 7 sections. For the first time a few of the endemic species known from Turkey were also given. Mobayen (1964) in his revison of the genus Acantholimon recognized 112 species in 7 sections (Pterostegia, Dracogyna, Acmostegia, Staticopsis, Armeriopsis, Glumaria and Tragacanthina) and described a few of the endemics known from Turkey. Bokhari (1970, 1972a) carried out taxonomic studies on the genus and described six new species in Acantholimon (A. confertiflorum, A. halophilum, A. reflexifolium, A.dianthifolium, A. hypochaerum and A. strigillosum) from Turkey and constructed an infrageneric grouping on the basis of morphological properties including the stigma and the pollen types (Bokhari 1972b). In Turkey, the first revision of Acantholimon was prepared by Bokhari & Edmondson (1982) in Davis’s Flora of Turkey and the East Aegean Islands in which they recognized 25 species in 3 sections. A new synopsis of Acantholimon in Turkey was given on the basis of a revisionary study conducted by Doğan & Akaydın (2007). In this study an account of 52 species, 10 subspecies and 17 varieties was presented including keys to the species, subspecies, varieties and a general indication of their distribution, as well as their conservation status in Turkey. Posteriorly, three new Acantholimon species were described and published (Bağcı et al. 2009, Yıldırım & Crespo 2014, Iğci et al. 2017). Accordingly, the genus Acantholimon is currently represented by 55 species, 10 subspecies and 17 varieties in Turkey. During the floristic surveys in Demirkazık (Çamardı, Niğde, southern Turkey) in July 2008, noteworthy specimens of Acantholimon, which showed branched scapes and white petals, were collected for the first time on calcareous slopes. Similar plants were discovered in 2017 at higher altitudes (1900 m) in a second survey in the same area. All collected specimens looked at first sight like A. davisii Akaydın & Crespo (2018: 80) [A. caryophyllaceum subsp. parviflorum Bokhari (1970: 299), A. parviflorum (Bokhari) Akaydın & Doğan (in Doğan & Akaydın 2007: 414), nom. illeg., non Regel (1882: 73)], but surprisingly their scapes were branched and petals were white in colour.