Loncomelos koprulense (Asparagaceae), a new species from southern Turkey

Abstract A new species, Loncomelos koprulense (Asparagaceae), is described and illustrated from southern Turkey. It is a very rare endemic species growing on small semi-rocky escarpments within the Köprülü Kanyon in the province of Antalya. Morphologically for its hairy leaves, L. koprulense shows some relationships with L. malatyanum and L. tardum, species localized in Anatolia too. The chromosome number of the new species is 2n = 2x = 22. Geographical distribution map for L. koprulense, L. malatyanum and L. tardum is provided.


Introduction
The genus Ornithogalum L., on account of its remarkable morphological and karyological variability, has been the object of various taxonomical treatments, which led to the recognition of several subgenera, sections and series or its splitting into different genera (Rafinesque 1840;Salisbury 1866;Speta 1998aSpeta , b, 2001Pfosser and Speta 1999;Manning et al. 2009;Martínez-Azorín et al. 2009). Recently, phylogenetic investigations based on morphological and molecular approaches carried out by Martínez-Azorín et al. (2011) emphasized that the hierarchical arrangement partly delineated by Speta (1998a) must be pursued, recognizing 19 monophyletic genera within the subfamily Ornithogaloideae Speta, all of which are morphologically well characterized. This approach was followed by Bogdanović et al. (2020) who widely analyzed the taxonomic aspect regarding these groups of Ornithogaleae J.C.Manning and Goldblatt. One of the accepted genera of this tribe, quite widespread in the Mediterranean territories, is Loncomelos Raf. showing in particular close relationships with Ornithogalum L. s.str. Morphologically, Loncomelos is mainly characterized by having inflorescence arranged in an elongated raceme, with pedicels more or less equal at maturity, capsule ovate-lanceolate, trigonous or trilobate with blunt or slightly retuse edges in cross section, seeds polygonal or irregularly compressed, with tuberculate, papillate or rugose testa, while Ornithogalum is differentiated by inflorescence corymbose or racemose-corymbose, capsule obovate or oblong, deeply trilobate with six evident ribs in cross section, seeds globose, with sinuous and prominent reticulate testa (Speta 1998a;Martínez-Azorín et al. 2011).
Currently, Loncomelos is represented by ca. 32 taxa, formerly mostly attributed to Ornithogalum, which are characterized by a very variable chromosome complement differing among the species, from diploid to polyploid and even aneuploid assets with 2n = 14, 16, 18, 20, 22, 24, 26, 28, 32, 36, 42, 44, 46, 52, 54, 88 (Cullen and Ratter 1967;Wittmann 1985;Speta 1998aSpeta , 2006Speta , 2010Speta , 2011Mutlu and Karakuş 2012;Kypriotakis et al. 2018;Bogdanović et al. 2020). In the frame of taxonomic investigation on the genus Loncomelos, it is herein examined a very peculiar population collected in the southern Turkey, between Antalya and Manavgat. Based on careful morphological, anatomical and karyological observations, it was concluded that this new geophyte is taxonomically quite isolated, only showing some similarities in its hairy leaves with L. tardum Speta and Ornithogalum malatyanum Mutlu (here considered as a member of Loncomelos), both occurring in Turkey (Speta 2006;Mutlu and Karakuş 2012). Therefore, it is described herein as a new species and named L. koprulense.

Materials and methods
The morphological study on the new species was carried out on living material collected from the locus classicus and cultivated in the Botanical Garden of Catania (Italy). Voucher specimens are deposited in the herbarium CAT (abbreviation follows Thiers 2020). Qualitative and quantitative morphological features were measured and scored on ten fresh plants, using a Zeiss Stemi SV11 Apo stereomicroscope at 6-66× magnification. Morphological comparison with the most related species was carried out using literature data (Speta 2006;Mutlu and Karakuş 2012). The diagnostic traits of the new species and its two allied ones are shown in Table 1.
Leaf anatomy was studied on cross-sections from cultivated plants, using fresh blades of minimum sized and maximum sized leaves in their optimal vegetative phase.
Phenology. Flowering in June and fruiting in June-July. Etymology. The species epithet is derived from the name of the Köprülü Kanyon, locality where this geophyte was collected.
Karyology. All investigated samples of Loncomelos koprulense from the type locality revealed a somatic chromosome complement with 2n = 22 (Fig. 3A). The karyotype is rather asymmetrical, comprising 11 chromosome pairs (Fig. 3B), arranged in two size groups where the submedian type prevails, as highlighted by the values of different symmetric indices (Table 2). In particular, there are 3 metacentric pairs, 3 metasubmetacentric pairs (showing arm ratio exceeding 1.30), and 5 submetacentric pairs (3 big-sized and 2 small-sized). Thus, the chromosome formula can be expressed as 2n = 2x = 22 = 6 m + 6 msm + 10 sm. No evident satellites were detected. Absolute chromosome length varied from 11.1 ± 1.3 μm of the longest chromosome and 4.26 ± 0.3 μm of the shortest one, with a mean chromosome length of 6.99 ± 2.2 μm. Relative chromosome length varied from 7.24% ± 0.8 to 2.78% ± 0.2. Arm index varied on average from 1.03 to 2.76, while the centromeric index ranged from 49.3 to 26.6. All karyomorphometric parameters are given in Table 2.
Leaf anatomy. The known Loncomelos species are usually differentiated by their canaliculate leaves, uniformly colored with dorsi-ventral arrangement, presenting differences in size in the same individual. In particular, the leaf outline is smooth in adaxial faces and more or less ribbed in the abaxial one, with epidermal cells covered by a thickened cuticle; the pallisade tissues is one-layered and distributed Abbreviations: TAL = total absolute length; TRL = total relative length; AR = arm ratio index; CI = centromeric index; Type = chromosome nomenclature; TCL = total chromosome length; MCL = mean chromosome length; d-value = difference between long arms and short arms; DRL% = difference of relative length; S% = relative length of shortest chromosome; MAR = mean arm ratio index; MCI = mean centromeric index; Cv CL = coefficient of variation of chromosome length; Cv CI = coefficient of variation of centromeric index; MCA = mean centromeric asymmetry. along the whole perimeter, while the inner part is occupied by the spongy tissue (Wittmann 1985;Tornadore 1985Tornadore , 1986Tornadore and Orza 1987;Lynch et al. 2006;Peruzzi et al. 2007;Öztürk et al. 2014;Bogdanović et al. 2020). The vascular bundles are arranged in two rows all along the mesophyll; large vascular bundles occur in the central part, which are alternated with other smaller one towards the abaxial side. The large bundles are interspersed with mucilage cells that are replaced by rhexigenetic lacunae in the mature leaves. Most species have completely glabrous leaves, except for L. tardum, L. malatyanum (see below for nomenclatural validation) and L. koprulense, showing a dense hairiness on the abaxial face. As a whole, the leaves of L. koprulense maintain the main features of the genus, revealing a marked variability in size; the largest leaves are characterized by 17-18 large vascular bundles, interposed among lacunae; these bundles decrease in number in the progressively narrower leaves up to a minimum of ca. 9, while the number of small vascular bundles coincides with that of the mesophyll lacunae (Fig. 2F). As far as hairs are concerned, they are irregularly distributed along the margin and on the abaxial face.
Ecology and distribution. Loncomelos koprulense seems to be a very rare species currently know only for a single locality of southern Turkey. One small and well circumscribed population was surveyed along the Bozyaka road within the Köprülü Kanyon at about 150 m of elevation (Fig. 4), where it grows on small semi-rocky escarpments covered by a scarce herbaceous vegetation. The woody vegetation near this habitat is represented by a thermophilous maquis characterized by Quercus calliprinos Webb, Olea europaea L. subsp. sylvestris (Mill.) Rouy ex Hegi, Pistacia terebinthus L., Juniperus oxycedrus L., Myrtus communis L., Arbutus andrachne L., Cupressus sempervirens L. etc.    Discussion. From the literature data (Zahariadi 1977(Zahariadi , 1980Wittmann 1985;Martínez-Azorín 2008;Martínez-Azorín et al. 2009), the circumscription of the genus Ornithogalum within the tribe Ornithogaleae has always been problematic, emphasizing that the traditional morphological approach is not sufficient to discriminate the taxa at generic level. Recent phylogenetic studies carried out by Pfosser and Speta (1999) and Martínez-Azorín et al. (2011), based on cpDNA and nrDNA gene sequences, have provided a relevant support for a taxonomic arrangement of this tribe, validating the treatment previously proposed by Speta (1998a, b). As concern the genus Loncomelos, it is morphologically well differentiated from Ornithogalum s.str. by numerous and significant characters regarding the inflorescence, pedicel, capsule and seed. From the phytogeographical point of view, this genus is mainly distributed in the Mediterranean area with the higher concentration of species in the Balkan Peninsula and Anatolia. The last territory currently hosts 14 species (included the new one), that therefore can be considered the main centre of differentiation of the genus.
A very peculiar and significant morphological character occurring in Loncomelos koprulense is the densely hairy leaves (Fig. 5D-E). In fact, most species of the genus Loncomelos are characterized by glabrous leaves, while only L. tardum and L. malatyanum have hairs on the leaves. According to Speta (2006) and Mutlu and Karakuş (2012), both species occur in Anatolia too, where they are very rare and quite localized (Fig. 4). They differ from L. koprulense in some relevant morphological features (Table 1), such as the shape and size of the bulbs, number of leaves, inflorescence size, number of raceme flowers, bracts, tepal shape and colour, tepal margin, stamen filament, size and shape of ovary and capsule. Differences were also observed in karyological aspect, since L. tardum is characterized by a chromosome complement of 2n = 2x = 20, reported by Speta (2006), while according to Mutlu and Karakuş (2012) the chromosome number of L. malatyanum is 2n = 2x = 24. We found out that L. koprulense is also a diploid, but its chromosome number is 2n = 2x = 22, which is quite rare in the genus Loncomelos, so far only previously counted in L. fischerianum (Krasch.) Speta by Agapova (1977).