Ferula mikraskythiana Mátis, A.Z.Szabó & L.Bartha, 2017

Mátis, Attila, Szabó, Anna, Lyskov, Dmitry, Sramkó, Gábor, Kuhn, Thomas, Bădărău, Alexandru S. & Bartha, László, 2017, Validating the systematic placement of Eriosynaphe in the genus Ferula (Apiaceae: Scandiceae: Ferulinae) linked with the description of Ferula mikraskythiana sp. nov. from Romania, Phytotaxa 298 (3), pp. 239-252 : 244-250

Ferula mikraskythiana Mátis, A.Z.Szabó & L.Bartha , sp. nov. ( Fig. 4–8 ).

Type:— ROMANIA. Pădurea Dumbrăveni Reserve (Constanţa County, SV Dobrogea), on steep (45º) southwest-facing slope, with calcareous, rocky substrate, in Ponto-Sarmatic steppe habitat (Stipetum lessingianae Soό), surrounded by Jasminum fruticans thickets and Quercus pubescens dominated forests, N 43.975847°, E 27.986031°, elevation 89 m, 19 August 2015, Mátis et al. 665702 (holotype CL!) ( Fig. 5 ).

Plants perennial, herbaceous, polycarpic, up to 170 cm tall. Taproot ±cylindrical, up to 3 cm wide, with radial lateral branches, and running deep into the soil. Stems solitary (sometimes 1–2 additional, smaller flowering stem sprouting from the base), erect and solid, nearly cylindrical (slightly pressed laterally), up to 1.4 cm wide at the base (where encircled by the remains of the basal leaves’ sheats), and bulging at the nodes. Surface of stem smooth, glabrous, and glaucous due to a waxy covering that can be easily wiped off ( Fig. 4.g ). Sheaths erect, not inflated, and almost amplexicaule, the lowest ones from the stem up to 6.5 cm in length. Leaves radical, tripinnatisect and glabrous, broadly triangular in shape, dried by the flowering time. Leaf blades up to 39 cm long, nearly two times wide. Petioles solid, shorter than blades, up to 26 cm long. Leaf primary and secondary segments as well as terminal leaf lobes always petiolate. Petioles thickened at the joining point to the rachis. Terminal leaf lobes (3–)5–8(–9) mm wide, (4–)6–10(– 12) cm long, entire at margin, oblong-linear and apiculate, often folded and with slightly hooded tip. Lower branches of the stem alternate, upper ones verticillate. Number of ‘primary’ branches of the stem 5–8 (not regarding those in the same whorl with the central umbel). Inflorescence with highly complex and paniculate architecture. Umbels compound, without involucre, the lateral ones smaller (sometimes sterile, but mostly fruiting), and a part of them overtopping the central umbel. Length of peduncle of central umbel (5–)7–10(–12) cm. Umbellules without involucel, (8–)10–15(–17) in number in the central umbel. Pedicels of flowers highly unequal. Flowers typical for Apiaceae , actinomorphic, 5-merous, bisexual with epigynous floral parts. Calyx very reduced, with 5 small, obtuse teeth. Petals 5, acuminate, yellowish-greenish, 1–1.5 mm long, reflexed, the acuminate tip curved inward. Stamens 5, elongated and spreading when maturing, 1–1.5 mm long, anthers latrorse, 2-locular, dehiscing by longitudinal slits. Gynoecium with 2-locular inferior ovary. Styles 2, 0.5–1 mm, bending outward when maturing, stylopodium swollen, nectar producing. Fruits ovate or oblonceolate, compressed dorsally, 0–140 in number in the central umbel. Carpophore bifurcate close down to the base. Mericarps black, shiny, tomentose at commissural side and in the ventral furrows, (3.2–)3.6–4.2(– 4.5) mm wide, (6.2–)6.9–8.3(–8.6) mm long. Mericarp anatomy ( Fig. 8 ): Dorsal ridges poorly developed and three in number. Lateral ridges lost in the thickening margin of the mericarp. Two deep furrows on the ventral side of the mericarp separated by a well-developed ventral ridge. Six vittae distributed solitarily, four of them between the dorsal ridges, two of them beneath the ventral furrows.

Phenology: Basal leaves present in May–June in the form of a well-developed rosette, flowering during end of July–August, fruiting in September.

Diagnostic characters: F. mikraskythiana closely resembles E. longifolia both in its overall architecture and mericarp anatomy and in the lack of other such similar taxa, we hypothesise that they are close relatives though differ in a series of morphological and phenological characters ( Table 1.). F. mikraskythiana exceeds E. longifolia in the size of most of its vegetative characters (height, stem diameter, measures of leaves and the central umbel, etc.). Terminal leaf lobes of F. mikraskythiana are always long petiolate, broadly oblong-linear and apiculate, with slightly hooded tip, whereas those of E. longifolia shortly or not petiolate, narrower (linear to filiform) and acuminate. Flowering-fruiting stems of F. mikraskythiana are remarkably glaucous whereas such feature was not reported for E. longifolia though can be inferred based on personal photos and Fig. 3 . Flowering and fruiting periods for F. mikraskythiana and E. longifolia are June versus end of July–August and July versus September, respectively.

Biology: Perennial plant with a serotinal flowering period. Flowers entomophilous, protandrous, pollination system generalist. Fruiting umbellules often damaged by the caterpillars of Phaiogramma etruscaria ( Geometridae ). After the fruits mature, the whole stem breaks off the root and acts as a disseminating unit (tumbleweed). Attempts to germinate the fruits failed and thus chromosome number could not be determined. In order to assess the potential negative effect of the reduced and isolated population, seed viability of 50 (2 × 25) seeds was tested with a 1% tetrazolium chloride solution. Based on this test, 100% of the seeds proved to be viable which gives hope for future existence of the wild population.

Distribution and habitat: —The region where F. mikraskythiana grows can be interpreted as a westward continuum of the distribution range of E. longifolia ( Fig. 1 ). F. mikraskythiana grows between elevations of 78–114 m, on south-western steep slopes of 35–45° inclination. The surrounding terrain relief is remarkable for its Sarmatian limestone outcrops that fragment the soil made up from chernozems, levigated chernozems, rendzinas and regosols ( Lupaşcu et al. 2004). In the broader sense, F. mikraskythiana grows in a so-called ‘silvo-steppe’ vegetation formed by patches of open meso-xeric grasslands, xeric shrub communities and oak-eastern hornbeam forests out of which F. mikraskythiana mostly inhabits the grasslands.

Etymology: —The specific epithet refers to the ancient Greek name Mikrá Skythia (Μικρὰ ΣκΥΘΊα) of the historical region Scythia Minor or Lesser Scythia, where this species was found. This area, situated between the lower Danube River and the Black Sea, roughly corresponds to what is known today as Dobruja, a region shared by Romania and Bulgaria (Romanian: Dobrogea; Bulgarian: ДобруДЖА, Dobrudža). This is in contrast to the presumably related E. longifolia , distributed along the historical region known as Great Scythia (the Pontic-Caspian steppe of Ukraine, southern Russia, and western Kazakhstan).

Additional specimen examined (paratype): —The paratype specimen examined ( Fig. 6) contains one entire basal leaf collected in May 15, 2015 (The text from its label corresponds with the one from the holotype except for the date of collection).

Conservation status: —Based on the currently available data, we consider the new species F. mikraskythiana a restricted endemic to the Dobrogea Region of (Southeast) Romania, although future surveys of similar habitats from the adjacent Bulgarian area might yield additional population(s). The species’ single know population is fragmented into two subpopulations from two small grassland enclaves ( Fig. 1 ) surrounded by the Dumbrăveni Forest where in total 172 individuals were numbered on an area covering much less than 500 km 2. Therefore, the species should be classified as Endangered (EN), under criteria D (number of mature individuals fewer than 250), according to the International Union for Conservation of Nature (IUCN) categories and criteria ( IUCN Standards and Petitions Subcommittee, 2016). The current lack of grazing should be maintained for conservation purposes.

Molecular data: —Although the presumed close relationship between F. mikraskythiana and E. longifolia is tempting based on morphological characteristics, the molecular data neither reject nor confirm their putative relationship due to the poor resolving power of ITS sequences. Both taxa are nested in the same well supported clade ( Fig. 2 ) where the species-level relationships failed to be resolved. This phenomenon is frequently encountered in case of genera that presumably underwent recent radiation.

Figures

FIGURE 1. Location of the newly described Ferula species’ single known population shown at three geographical scales by white-filled circles. Gray-filled circles portray the distribution of the morphologically similar Eriosynaphe longifolia based on data from Herbaria CL, MHA, MW, SVER as well as on http://www.gbif.org/ and http://www.plantarium.ru/. The map was prepared in QGIS 2.14 (http://www. qgis.org).

FIGURE 2. Best Maximum Likelihood phylogram based on nrDNA ITS sequences of Ferula and relatives taken from Panahi et al. (2015) and supplemented with three newly generated sequences in boldface.Numbers adjacent to nodes (not shown below 70) represent bootstrap support percentages.

FIGURE 3. Photograph of E. longifolia taken in June 2015 in the surroundings of Vodnobuerachnoye village (Volgograd Oblast, Russia), close to the river Volga (by G. Sramkó).

FIGURE 4. Photographs of F. mikraskythiana. The habit (a), terminal leaf lobes (b) and leaf architecture (c) of the plant in May. Central umbel and lateral branches of the inflorescence (d) as well as habit of the whole plant in its natural habitat (e) in August. f, conserved terminal leaf lobes (scale bar: 1 cm). g, the glaucous stem with dried basal leaves (August). h, macrophoto of a flower conserved in ethanol-glycerol solution (scale bar: 1 mm) (by A. Szabó and A. Mátis).

FIGURE 5. Photograph of the holotype specimen of F. mikraskythiana (by B.-I. Hurdu)

FIGURE 8. Schematic fruit anatomy of F. mikraskythiana depicted by a mericarp transsection. a, exocarpium. b, mesocarpium. c, endocarpium. d, dorsal ridge. e, vascular bundle. f, vittae. g, seed coat (testa). h, endosperm. i, raphe. j, ventral ridge. k, ventral furrow. l, vascular bundle. m, thickened wing.