Galium shinasii (Rubiaceae): a new species of Galium L. from Eastern Turkey

Abstract Galium shinasii Yıldırım (Rubiaceae), is described as a new species from Malatya Province in eastern Anatolia, Turkey. The new species is morphologically related to Galium cornigerum Boiss. & Hausskn. Galium lasiocarpum and Galium sorgereae Ehrend. and Schönb. but clearly differs from them based on the morphological differences presented in the species description. In addition, the conservation status, the distribution map, and notes on the biogeography and ecology of the new species are given.


Introduction
Th e family Rubiaceae is the fourth-biggest angiosperm family with about 660 genera and 11.500 species (Robbrecht andManen 2006, Soza andOlmstead 2010). A large number of species of Rubiaceae are herbaceous and many are adapted to xeric habitats. (Robbrecht 1988, Jansen et al. 2000. Galium L. is one of the largest genera of the Rubiaceae, with about 650 species and approximately 780 taxa placed in 16 sections, including perennial and annual herbs that are distributed in temperate and tropical regions of worldwide (Willis 1985, Mabberley 1987, Goavert 2015. A total of 121 Galium taxa (104 species) are found in Turkey and 60 taxa (endemism rate of 50%) are endemic to this country (Karabacak 2012).
In June 2011, the second author collected an unusual and distinct specimen of Galium on marlstone-calcareous rocky cliff s in the Levent Canyon which authors believe to be of a new species for science.

Materials and methods
Specimens of the putative new species were compared with herbarium specimens at ANK, EGE, E, G, GAZI, HUB, ISTE, K, W and WU. In addition, the relevant literature (Halácsy 1901, Ehrendorfer and Krendl 1976, Ehrendorfer and Schönbeck-Temesy 1982, Davis et al. 1988, Ehrendorfer and Schönbeck-Temesy 2005, Govaerts 2016) was reviewed. Th e new species was examined by stereo-binocular microscope for morphological characterisation. At least 20 mature seeds and 30 pollen grains were measured using a light microscopy. For scanning electron microscopy (SEM), the selected seed and pollen grains were placed on aluminum stubs using double-sided adhesive tape, sputter coated with gold using an Emiteck K550, and then examined using the FEI Quanta250 FEG SEM. Photographs of living material were taken with a Nikon D300 digital camera. Th e conservation status of new species was evaluated based on the fi eld observations in accordance with IUCN guidelines (2012). Geographical positions were recorded using a Magellan explorist 500 GPS. Diagnosis. Galium shinasii is related to Galium cornigerum, G. lasiocarpum and G. sorgereae but it diff ers from them in having very reduced fl owers (not fl owers relatively larger), 1.2-1.8 mm corolla diam (not 2-5 mm); yellowish-green to reddish-green and 0,5-1 mm long tepals (not white or pink and not at least 2 mm); dorsal and ventral surface of with densely transparent tubercles and lateral surface 0.2-0.4 mm spreading to patent hairy fruits (not tubercles absent and fruits wholly villous, hirsute or subtomentose).
Etymology. Th is species is named in honour of retired Prof. Dr. Şinasi Yıldırımlı (Biology Dep. Hacettepe University, Turkey), who is an expert in Plant systematics and taxonomy. He described more than 100 new plant species for science in Turkey. Th e Turkish name of this species is given as "Levent İplikçiği", according to the guidelines of Menemen et al. (2013).  Distribution and ecology. Galium shinasii is a endemic for Eastern Anatolia. It's known that is from Levent Canyon ( Figure 5) in Akçadağ district, and Eskiköy in Doğanşehir district in Malatya province and near Refahiye district in Erzincan ( Figure  5). It is an element belonging to the Irano-Turanian fl oristic region and colonizes only marlstone-calcareous cliff s, usually those with an eastern and south-eastern orientation, at an elevation of 1200-1800 m. It is an obligate chasmophyte.
Suggested conservational status. Th e new species found in 3 populations. Two populations have been discovered in Malatya province, the other has been discovered in Erzincan province. Although the distribution area of Galium shinasii seems relatively wide, the populations of the area are very restricted. Th e total population area of G. shinasii was calculated as 0.2 km 2 and approximately 500 individuals were observed in total. Probably it has still several undiscovered populations. No anthropogenic or grazing eff ects were observed on the population. According to the present data, following the criteria laid out by the IUCN (2012), the plant is categorized as 'Vulnerable' (VU) D1 + 2, on account of its restricted distribution.

Discussion and conclusions
Galium shinasii is a member of Galium Sect. Orientigalium Ehrend. It is characterized by chasmophyte, dwarf caespitose habit, very fragile 2-6 cm long stems, mostly 4 rarely 6 leaves in a whorl; 1.5-6.5 cm long leaves; fl owers diam 1.2-1.8 mm; corolla yellowish-green to reddish-green; usually corolla lobes formed in a conical or campanulate corolla shape, very rarely lobes wholly opens and formed a infundibular corolla shape; fruit dorsal and ventral surface with densely transparent tubercles, lateral surface 0.2-0.4 mm spreading to patent hairy.
Although Galium shinasii shows some morphological similarities with G. lasiocarpum Boiss., G. sorgerae Ehrend. and Schönb., G. cornigerum Boiss. and Hausk. in sect. Orientigalium, it is easily distinguished from these by relatively smaller fl owers; yellowish-green to reddish-green and very reduced tepals; fruit surface is not only hairy on lateral surface, and also dorsal and ventral surface with densely transparent tubercles. Also it shows slight morphological similarities to G. incanum Sm. subsp. pseudocornigerum Ehrend. with dwarf caespitose habit, smaller leaves and in having fruits  lacking a calyx but it is easily distinguished from G. incanum. subsp. pseudocornigerum by its especially more reduced and diff erent coloured fl owers, a greater numbers fl ower number per stem; smaller, depressed subglobose and long-hairy fruits. Th e detailed of the morphological diff erences between Galium shinasii and related Gallium species are summarized in the Table 1.
After adding this new species in science literature, the total number of Gallium taxa were raised to 121 (105 species) in Turkey and 61 taxa are endemic for Turkey.