42 Accepted by Alexander Sennikov: 14 Jun. 2013; published: 3 July 2013 PHYTOTAXA ISSN 1179-3155 (print edition) ISSN 1179-3163 (online edition) Copyright © 2013 Magnolia Press Phytotaxa 115 (2): 42–48 (2013) www.mapress.com/ phytotaxa/ Article http://dx.doi.org/10.11646/phytotaxa.115.2.2 Centaurea stuessyi (Compositae: Cardueae), a new species from the eastern Iberian Peninsula ITZIAR ARNELAS 1 , JUAN ANTONIO DEVESA 2 & EUSEBIO LÓPEZ 2 1 Cuerpo Académico Diversidad de los Recursos Florísticos de Mesoamérica, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán. A. P. 4–116, Mérida, 97000 Yucatán, México; e-mail: itziarnelas2@gmail.com 2 Departamento de Botánica, Ecología y Fisiología Vegetal, Facultad de Ciencias, Universidad de Córdoba, Campus de Rabanales, Edificio José Celestino Mutis, ctra. de Madrid km. 396, 14071 Córdoba, Spain. Abstract Centaurea stuessyi is described as new to science from the eastern Iberian Peninsula, Spain. The range of this new species coincides with the zone of overlap of the ranges of two related species, C. antennata (subsp. antennata) and C. linifolia. The chromosome number found in the new species (2n = 44) reinforces its differences from C. linifolia (2n = 22) and C. antennata (2n = 22). The new species is compared with related species, and a description is given of its ecological preferences. Resumen Centaurea stuessyi se describe como una nueva especie para el este de la Península Ibérica. El área de distribución de la nueva especie coincide con el área de solapamiento de distribución de dos especies relacionadas con la nueva: C. antennata subsp. antennata y C. linifolia. El número cromosómico hallado para la nueva especie (2n = 44), refuerza la diferenciación de C. linifolia (2n = 22) y C. antennata (2n = 22). La nueva especie es comparada con las especies relacionadas y se describe las preferencias ecológicas de la misma. Key words: Asteraceae, Centaurea antennata, Centaurea linifolia, chromosome counts, Iberian Peninsula, Spain, taxonomy Introduction The genus Centaurea Linnaeus (1753: 909) is one of the most diversified of the Asteraceae family, and in its current circumscription comprises nearly 250 species (Susanna & Garcia-Jacas 2007) distributed mainly in the Mediterranean region and SW Asia, with a good representation in Europe and Africa. The group Jacea (Wagenitz 1955, Garcia-Jacas et al. 2001), the most diversified group in the genus with a number of subclades being recognized (Garcia-Jacas et al. 2000, 2006), includes C. sect. Jacea (Miller 1754: 663) Persoon (1807: 484) and C. sect. Lepteranthus (Candolle 1810: 158) Dumortier (1827: 73), whose definition has differed according to authors (vide Willkomm 1865, Dostál 1976, Arnelas & Devesa 2011) and whose recognition has not been supported by phylogenetic studies (Garcia-Jacas et al. 2006). Centaurea sect. Lepteranthus includes the species in which the appendage is linear-subulate or triangular- subulate, and usually more or less arcuate-reflexed. Its taxonomic knowledge in the Iberian Peninsula is mainly based on the generic treatments of Willkomm (1865), Dostál (1976) and especially on the work of Arnelas & Devesa (2012), together with various partial contributions that have gone towards completing those treatments (Laínz 1967, 1976, Bolòs & Vigo 1988, 1995, López-Alvarado et al. 2012), as well as on studies of its chromosomal (Gardou 1972, Fernández Casas 1976, Valdés Bermejo & Gómez García 1976, Fernández TERMS OF USE This pdf is provided by Magnolia Press for private/research use. Commercial sale or deposition in a public library or website is prohibited.