Oenanthe millefolia (Umbelliferae), a new species record for the Turkish and Greek Flora

Abstract Oenanthe millefolia (Apiaceae), which is presented as a new recorded species for the Turkish flora, was discovered for the first time in Kırklareli province of Turkey. It is also reported as a new species for the Greek flora based on an unidentified specimen which was collected from the Thrace region of Greece. In this study, an expanded morphological description, the geographical distribution, the habitat properties and the ecological features of the species are exhibited with illustrative figures. Moreover, the micromorphological and anatomical characters of the fruits and the anatomical properties of the stem, petiole, leaves and the palynological features of Oenanthe millefolia are determined and described for the first time.


Introduction
Th e genus Oenanthe L. is represented by nearly 35-40 species in the world and 8 species in Turkey (Hedge andLamond 1972, Duman 2000). According to Menemen (2012), Oe. incrassans Bory & Chaub., which is considered as a synonym of Oe. pimpinelloides L. (Hedge and Lamond 1972), was uncertainly recorded from Turkey. However, the fi rst author of this paper (Doğan Güner 2016) recently confi rmed its occurrence in Turkey.
Some unusual specimens were collected from the Kırklareli province of Turkey during a project dealing with the revision of Turkish representatives of the genus Oenanthe. Th ese specimens were clearly diff erent from all the taxa of the genus distributed in Turkey (Hedge andLamond 1972, Duman 2000). After consulting literature dealing with the fl ora of the adjacent regions and checking the herbarium vouchers, these materials were preliminarily identifi ed as Oe. millefolia Janka (Cook 1981). However, these specimens were also similar to Oe. bulgarica Velen., which was described by Velenovsky (1898). Detailed investigations of literature and the herbarium vouchers show that Oe. millefolia and Oe. bulgarica are morphologically very similar taxa (Velenovsky 1898, Hedge and Lamond 1972, Cook 1981, Duman 2000. Moreover, Oe. bulgarica has already been synonymised under Oe. millefolia by Gandoger (1910) in his "Novus conspectus fl orae Europae". With this species, the total number of the Oenanthe species in Turkey is now 10.
Th e aim of this study is to describe morphological, anatomical, palynological and fruit micromorphological properties of the species.

Methods
Th e specimens, collected during the fi eld studies in Igneada-Kirklareli region in 2014 and 2015, were checked with the related literature (Velenovsky 1898, Gandoger 1910, Hedge and Lamond 1972, Cook 1981, Duman 2000. Th e specimens of Oe. millefolia were compared with the type specimen and the other representative vouchers kept in GOET, E, SOM, W, and WU herbaria (abbreviations following Th iers 2016).
All the samples which were used for the anatomical studies were fi xed in 70% ethanol during the fi eld works. Th ey were stained using sartur reagent according to the method described by Çelebioğlu and Baytop (1949). Th e stained samples were examined under an Olympus E330 microscope and the anatomical properties were clarifi ed. Moreover, related literature was used for the explanation of the anatomical characters (Mauseth 1988, Dickison 2000. For the palynological studies, pollen slides were prepared according to the Wodehouse method (1935) and were examined under a light microscope (LM). Diff erent 30 pollen grains were measured by using a Leica DM3000 microscope. Th e pollen samples and mericarps were directly placed on aluminium stubs and coated with gold with Polaron SC 502 Sputter Coater device and observed with the Jeol JSM 6490LV model scanning electron microscope (SEM). For the palynological and micromorphological terminology, Moore et al. (1991), Punt et al. (2007), Hesse et al. (2009) and Doğan Güner et al. (2011) were used. Description. Perennial, 40-70 cm tall, herb, with thickened, fusiform or oblong tubers, tubers generally at stem base, rarely far away. Stem erect, simple or 3 times branched above, hollow, furrowed, minutely scabrid below, glabrous above. Basal leaves lanceolate or oblong in outline, 2-3 pinnate, 17-45 × 5-9 cm, leaves lamina longer than petiole; segments of lamina opposite at rachis, deeply pinnatisect, ultimate segments linear or elliptic up to 6 × 1 mm, excurrent into a setaceaus tip. Upper leaves similar to basal one, but only a few which reduce upwards. Umbel with 12-18 slender rays of sub-equal length, up to 2 cm, becoming slightly thickened in fruit. Umbels 5 cm diam. at fl owers and 3 cm diam. at fruit. Bracts 8-9, lanceolate, 8-10 × 1.5-2 mm. Umbellules conical with unequal thickened pedicels in fruit, 20-30 fl owered, about 1-1.5 mm diam., pedicels of sterile fl owers longer than fertile ones. Bracteoles 9-13, elliptic-linear, 2-3.5 × 0.5-1.5 mm. Petals radiating, white, cordate, to 2.5 mm long. Sepals ovate, 0.3-0.4 mm, acuminate at apex. Filaments at least two times longer than petals. Stylopodium is conical and not exceeding calyx teeth. Styles about as long as the body of the fruit (ca. 3 mm), erect. Fruit ovate to cylindrical, 3 × 2 mm, striate, laterally and base of fruit slightly spongiose margin.

Oenanthe millefolia
Distribution, habitat and ecology. Oenanthe millefolia is distributed in Bulgaria, North-eastern Greece and European Turkey (Fig. 1) Mericarp macromorphology and micromorphology. Mericarps have three dorsal and two lateral primary ribs. Th e lateral ridges are more prominent and broader than the dorsal ones. Th e lateral ridges extend towards the base and cover the base of mericarp. Sepals are generally distinctive and persistent in Oenanthe species. Stylopodium is conical and not exceeding calyx teeth. Stylopodium ending with style is almost as long as the fruit. Th e surface ornamentation of the pericarp is longitudinally striate. Th e pattern is formed by rectangular cells. Stomatal cavities are observed on the pericarp surface and the density increases towards the calyx (Fig. 3). Th e style surface is ribbed.
Anatomy. Stem anatomy: Stems are circular and slightly 7-8 ribbed in cross sections. Th ere is a thin layer of cuticle on the top surface and a single-line epidermis composed of rectangular cells underneath. Collenchyma cells are grouped at the edges. Cortex parenchyma cells are located around disordered collenchyma cells. Collenchyma  and parenchyma cells are identifi ed as two layers between edges. Collenchyma has 4-5 rowed, small, and circular cells. Parenchyma has 1-2 rowed, large and circular cells. Secondary slight edges are located between the edges with collenchyma cells. Secretion canals exist in cortex under the collenchyma layer. 5-6 cells in one line surround the canals. Endoderm cell walls are slightly thick one-line oval cells. Vascular bundles are embedded between the cortex and the pith. Th ere are 6-7 rows of sclerenchymatic cell layers between the vascular bundles. Peripheral vascular bundles which are collateral, are large against the edges and small in between the edges. Central vascular bundles are connected with peripherals by sclerenchymatic tissue. Secretion canals are also found under vascular bundles. Slight thickening is seen in pith parenchyma cells. Pith cells have various sizes with large inter-cellular spaces (Fig. 4A-B).
Petiole anatomy: Petiole is almost straight in cross section, ovoid in outline and slightly-canaliculate on the lower surface. Scabrid hairs rarely occur between cubic epidermis cells. Cuticle, epidermis and collenchyma structures are designed in almost the same manner as the stem. Secretion canals between collenchyma and concentric vascular bundles are signifi cant. Xylem elements are dominantly distributed. Th e pith is composed of large circular cells with a hollow centre (Fig. 4C-D).
Leaf anatomy: Th e epidermal layer consists of rectangular or circular cells in both adaxial and abaxial directions. Stoma exist on both surfaces. Th ere are large respiratory spaces under the stomata. Mesophyll is composed of two-row palisade and one or two-row sponge parenchyma cells. Large ventilation spaces exist between sponge parenchyma cells. Xylem elements are located through the abaxial side and phloem elements are located through the adaxial side ( Fig. 4E-F).
Fruit anatomy: Th e fruit is schizocarp with two mericarps. Th e pericarp forms a thin layer around the endocarp and seed. Th ere are single-line and horizontally located epidermal cells on the surface. Th e mesocarp is formed by 2-3-row small cells. Both epidermis and mesocarp cells have signifi cant thickness. Five ridges are seen on each mericarp. Vascular bundles are located on these ridges. Th ey are reduced. Secretion canals are located on vascular bundles. Pericarp is surrounded with sclerenchymatic tissue which makes a continuous ring up to the carpophore. Th e sclerenchyma layer is composed of irregular cells with thick walls. Th ere are 4 dorsally and 2 ventrally vittae. Oval-shaped vittae are located in the vallecular region. Endoderm is located as one line under the vittae and seems to be integrated with the testa. Th e seed is composed of endosperm and testa with a thickened cell wall. Endosperm contains large quantities of lipid and protein. Th ere are many druse crystals in the endosperm. When the section is taken from the middle of the mericarp, the embryo cannot be observed because it is small and close to the tip (Fig. 4G-H).

Discussions
After detailed investigations on the descriptions of Oe. millefolia and Oe. bulgarica, it was found that these two taxa are conspecifi c. Gandoger (1910) also previously recognised Oe. bulgarica as the synonym of Oe. millefolia. However, Cook (1981) did not mention the synonymy of Oe. bulgarica under Oe. millefolia in Flora Europaea.
Th e leaf lamina of Oe. millefolia is deeply pinnatisect, comprising primer segments with shorter and denser ultimate segments. Th e primer segment is also remotely and evenly distributed to the apex (Fig. 2D). Th is leaf morphology clearly resembles the leaf of Oe. tricholoba Greuter (Greuter 2012). Oe. tricholoba has however ± globular root tubers which are distant from the base of stem (not fusiform or oblong tubers and not very close to the base of the stem).
In this study, the morphological description of the species has been expanded with investigated specimens (especially our collections, the specimens of W and WU herbaria and the photographs of the specimens from GOET, SOM, E herbaria). Some of the morphological characters show high variations. In our collected specimens, root tubers are generally close to the base of the stem but some of them are remote (not only at base of stem), basal leaves 2-3 pinnate (not 2-pinnate) and umbels with 12-18 rayed (not 5-15 or 10-16).
During the studies on the specimens of diff erent herbaria, we realised that one unidentifi ed specimen deposited at E herbarium is identical to Oe. millefolia. Th is specimen was collected from Greece. With this additional record, the distribution of Oe. millefolia, so far known as a Bulgarian endemic, has been extended southwards to Turkey and Greece. Th erefore, the species should be considered as a Balkan endemic.
Th e species of Oenanthe in Turkey, mostly prefer wetlands and humid areas. It has however been observed that Oe. pimpinelloides is distributed in dry areas such as under trees or open woodlands in addition to the aquatic habitats. Moreover, Oe. millefolia is observed only in dry areas with Oe. pimpinelloides. Th is study comprises the discovery of Oe. millefolia in the Th racian regions of Turkey and Greece. To date, there has been no comprehensive study dealing with Oe. millefolia. Th is paper provides micromorphological, anatomical and palynological features of the species along with its expanded morphological description. Th e fi ndings of this study can contribute to further taxonomical investigations on both the genus Oenanthe and family Apiaceae.