Usefulness of palynomorphological characteristics for the identification of species Cyanus Mill. (Asteraceae) in Turkey: a taxonomic approach

Abstract

IntroductionThe family Asteraceae is the largest and the most cosmopolitan of the flowering plants and is presumably the most widespread in the Mediterranean (Attard and Cuschieri, 2009). Centaurea L., is a large genus belongs to the tribe Cardueae, comprises approximately 250 species (Susanna and Garcia-Jacas, 2009) and of its 181 species are growing in Turkey (Uysal, 2012), and since then, the number of the taxa has reached 205, with the latest additions (Şirin et al. 2020). Worldwide, the subgenus Cyanus is represented by about 25 species (Hellwig, 2004) and 21 of them are distributed in Turkey (Uysal, 2012).Recent definitions of Centaurea (Susanna and Garcia-Jacas, 2009) include the subgenera Acrocentron, Centaurea, and Cyanus, and although the sister relationship of the latter two has been clearly established, the relationships between them and Acrocentron remain unclear (Susanna and Garcia-Jacas, 2009). Miller (1754) first taxonomically described Cyanus as a genus. Following that, then reassigned the group as a section of Centaurea (De Candolle, 1838), which has been accepted extensively by taxonomists (Bentham, 1873;Boissier, 1875;Wagenitz, 1975). Cyanus is now generally accepted as a subgenus (Hilpold et al., 2014) and very rarely, as a group (Wagenitz and Hellwig, 1996;Garcia-Jacas et al., 2001) within Centaurea, although some researchers have still insisted on it being a genus (Greuter, 2003;Bancheva and Greilhuber, 2006). Distribution of theCyanus group lies across central and southern Europe, North Africa, Anatolia, and the Caucasus. Moreover, some species occur in areas of Iran and Afghanistan (Boršić et al., 2011). Within the scope of the current research, Cyanus was considered as a subgenus, based on current molecular studies (Şirin et al., 2019).Florets in this group are blue or purplish blue in color, with a few taxa having been reported as cream or pale pink, which is highly exceptional for the subtribe Centaureinae. Additionally, the most unusual characteristic is the phyllary appendages, which are non-spiny and decurrent almost down to the base (Wagenitz and Hellwig, 1996). This group also has some significant characteristics in common with groups Jacea and Acrocentron. It has marginal florets that are sterile and do not comprise staminodes, and the seed has a lateral hilum (Garcia-Jacas et al., 2001;Şirin et al., 2017).Aside from its morphological characteristics, the Cyanus group is also distinguished by having two pollen types. In a study by Wagenitz (1955), it was reported that of the eight types of pollen in Centaurea s.l., two types were identified in Cyanus subgroups. One of the subgroups comprises annuals that have the Cyanus pollen type, while the other subgroup comprises perennials that have the Montana pollen type (Figure 1). Species of the subgenus Cyanus have been examined by various researchers in recent years (

Palyno‐taxonomic approach through light and scanning electron microscopy for the identification of herbaceous Asteraceae species from Sikaram Mountain Pak‐Afghan border

“…The Asterales pollen‐morphometric characters were contributing to the morphological disparity among the Asteraceous taxa, which separates closely related taxa (Jardine et al, 2022). Microcharacters including palynological and anatomical attributes were significantly considered in the identification of problematic taxa with their inter‐relationship with other taxa (Abbas et al, 2022; Çitak et al, 2021; Majeed, Ahmad, Ozdemir, et al, 2023), whereas they also assess in the classification of morphologically closely related taxa at tribe, genera, sections, and subspecies levels (Majeed et al, 2022; Shaheen et al, 2018; Via do Pico et al, 2016). Recently, pollen features were applied as phylogenetic traits in the identification and classification of phenotypically similar taxa within the groups (Majeed, Ahmad, Ali, et al, 2023; Younis et al, 2021).…”