Orobanche mayeri ( Suess . & Ronniger ) Bertsch & F . Bertsch – a species new to Poland

Orobanche mayeri (Suess. & Ronniger) Bertsch & F. Bertsch, Mayer’s broomrape, is one of the rarest representatives of the family Orobanchaceae in Europe. It was known only from single localities in Germany, Slovakia and Romania prior to this report. It is red-listed as a threatened species in Baden-Württemberg [1] and Germany: (category R) [2], as a highly endangered of extinction [3], as well as in Slovakia (category LRr) [4]. It is considered to be threatened in central Europe (Verantwortlichkeit Mitteleuropas, VME) [5,6]. The species was discovered by the botanist and pharmacists Adolf Mayer (1871-1952) from Germany in Zeller Horn in the Swabian Alb in Baden-Württemberg in 1940 and incorrectly determined as O. elatior. It was later revised by Süssenguth and Ronniger [7] and identified as O. alsatica var. mayeri. The taxon, considered to be endemic, was known only from one locality in Europe. It was later recorded at over ten localities in the Slovakian Carpathians in the 1990s [4].


Introduction
Orobanche mayeri (Suess.& Ronniger) Bertsch & F. Bertsch, Mayer's broomrape, is one of the rarest representatives of the family Orobanchaceae in Europe.It was known only from single localities in Germany, Slovakia and Romania prior to this report.It is red-listed as a threatened species in Baden-Württemberg [1] and Germany: (category R) [2], as a highly endangered of extinction [3], as well as in Slovakia (category LRr) [4].It is considered to be threatened in central Europe (Verantwortlichkeit Mitteleuropas, VME) [5,6].
The species was discovered by the botanist and pharmacists Adolf Mayer  from Germany in Zeller Horn in the Swabian Alb in Baden-Württemberg in 1940 and incorrectly determined as O. elatior.It was later revised by Süssenguth and Ronniger [7] and identified as O. alsatica var.mayeri.The taxon, considered to be endemic, was known only from one locality in Europe.It was later recorded at over ten localities in the Slovakian Carpathians in the 1990s [4].

General distribution
Orobanche mayeri is a rare species associated mostly with the flora of the Western Carpathians, especially with the area of the Central Carpathians [4].Its distribution is not fully known.
Orobanche mayeri was first reported from Germany [7].It was treated as an endemic taxon but was later recorded at over ten localities in Slovakia in the Carpathians.It was mostly recorded in the Nizkie Tatra Mts (district: Demänovská dolina, Liptovský Hrádok, Krakova hola, Malužiná, Čierny Váh) and was collected at one locality in the Choczańskie Góry Mts (Kvačianska valley) and at three localities in the Western Beskidy Mts in Orava [4].
The complex of morphologically similar species treated as O. alsatica agg., in which O. mayeri is included, requires special and critical taxonomic revision.The species is also morphologically similar to O. flava [4].A list of characters differentiating the species within the O. alsatica agg. is given in a study by Pujadas-Salvá and Gómez-Garciá [8].
Although it was described by Süssenguth and Ronniger [7] as a variety of O. alsatica and reported as a subspecies in Kreutz [12], Rothmaler [13] and Pusch and Günther [10].O. mayeri seemed to differ sufficiently by distinct morphological and ecological characters that it could be raised to the rank of species.This was done by Bertsch and Bertsch [11] and the rank was later accepted by Hepp [14], Nieschalk and Nieschalk [15], Zázvorka [4], Senghas and Seybold [16] as well as Pujadas-Salvá and Gómez-Garciá [8].
In the original description of O. alsatica subsp.mayeri, Süssenguth and Ronniger [7] report bright yellow taxa.However, only a few plants were yellow at the locus calssicus while the colour of most specimens ranged from light to dark brown [12].Pink-red or reddish plants are also reported by [4].Many species of the genus Orobanche, including those within the O. alsatica sensu lato group, are often yellow; however, they almost never constitute the majority of a population.Such pigmentation is not typical and is a result of the insolation rate or incomplete plant pigmentation.Yellow and albinotic varieties can usually occur in more shaded sites.

Biology and habitat conditions
The locality in Zeller Horn, is situated in a NW-facing mountain meadow (840-900 m).Orobanche mayeri grows on calcareous, loamy soil, with solitary beech trees.The area was declared a protected nature reserve in 1950 and is one of the most important plant habitats in the Swabian Alb [12].It grows in Germany in the ass.Bupleuro longifolii-Laserpitietum latifolii (Geranion sanguinei, Origanetalia) [13] (Uhlich personal communication, 2009).
O. mayeri grows at altitudes from 650 to 1000 m, maximum 1500 m, at the localities in Slovakia.It usually occurs on S-facing habitats, on grassy slopes, overgrowing rocks, in relict pine groves and thinned spruce forests as well as in relict montane xerothermic grasslands on dolomites and limestone.In Slovakia the plant grows in Erico-Pinion (= Pulsatillo slavicae-Pinion) and Laserpitio-Calamagrostietum variae (Seslerietalia).It is often accompanied by O. reticulata [4].
O. mayeri flowers from the end of June until the end of July (August) [4,12].Laserpitium latifolium is its exclusive host [10,12].Zázvorka [4] additionally reports another host plant, Pimpinella major subsp.rhodochlamys, from the locality in Ohnište in the Nizkie Tatra Mts.

Methods
Field studies were carried out in July in 2009.The localities are situated in the Western Carpathian province, Central Western Carpathians subprovince, Obniżenie Orawsko-Podhalańskie depression macroregion, Pieniny mesoregion [17].The distribution of its localities was mapped using the ATPOL grid based on cartogram units 10 × 10 km [18].
The nomenclature of the vascular plant species listed in the phytosociological table follows Mirek et al. [19] and the nomenclature of syntaxa is used after Matuszkiewicz [20].Phytosociological relevés were conducted using the Braun-Blanquet method [21].

New localities
Two localities of O. mayeri, separated by 1.5 km in a straight line, were recorded in southern Poland in the Central Pieniny Mts, ATPOL EG33 (Fig. 1, Fig. 2).BIAŁE SKAŁY.The ecotone zone of an overgrowing rock grassland and a thinned oak-hornbeam forest on the S-facing slope of the Białe Skały rocks, near the blue tourist trail, 49°25'31.A detailed list of species recorded at the localities is given in Tab. 1.

Conclusions
The calcareous substrate, the exceptional geomorphological and microclimatic differentiation, the absence of glaciation, the vicinity of the Tatra Mts and calcareous Slovakian  ranges and, consequently, migration opportunities between the ranges, and the low altitude of the range influence a high differentiation of the vegetation in the Pieniny Mts.Relicts, that is plants that have survived at their localities from the earliest geological periods and live in isolated populations at considerable distances from their range limits, also occur in the area.
Orobanche mayeri grows in the Pieniny Mts in rock grassland communities, especially in the ecotone zone of two classes that represent them: xerothermic grasslands of Festuco-Brometea class and montane grasslands Seslerietea variae developing on calcareous substrate.In the former, Dendranthemo-Seslerietum variae, a rock montane grassland and an endemic association in the Pieniny Mts, is particularly interesting.Scrub and forest species of the Trifolio-Geranietea sanguinei and Querco-Fagetea classes often occur in the communities occupied by O. mayeri.This is associated with progressing secondary succession and the mosaic pattern of phytocoenoses (Tab.1).
Communities occupied by O. mayeri in Germany and Slovakia are similar to Polish localities.They are rare communities of the Geranion sanguinei, Seslerietalia or Erico-Pinion [4,16].It should be added that the occurrence of range limit and impoverished forms of communities of the Erico-Pinetea class in the Polish Pieniny Mts has been the subject of several controversies and requires further investigation [20].
The species grows to a height of 35 to 45(55) cm at its localities in Slovakia [4] and up to 60 cm in Germany [12].It was between 22 and 60 cm tall at the Polish localities.
As a rarely occurring species with a small distribution range, O. mayeri is highly threatened in Europe.Additionally, populations at its localities are not numerous.Only two specimens were recorded in Zeller Horn in 2008 [22], nine in 2009 (Uhlich personal communication).Its populations range from succession and the proximity of tourist trails pose a threat to the species.
1"N/20°25'19"E, alt.725 m.Species of the Querco-Fagetea class dominate in the community with a very small participation of the Seslerietea variae, Festuco-Brometea and Trifolio-Geranietea sanguinei classes.Only five specimens were recorded.TRZY KORONY.S-, SE-and SW-facing rock ledges and cliffs below the Okrąglica summit, 49°24'49.4"N/20°24'51"E,alt.915-967 m.The species is scattered in a xerothermic grassland of the Festuco-Brometea class in the ecotone zone with rock grasslands of the Dendranthemo-Seslerietum ass.(Seslerietea variae class); with a high occurrence of species of the Trifolio-Geranietea sanguinei and Querco-Fagetea classes.A total of ca. 30 specimens were recorded.The majority of the specimens were observed in an open, S-facing xerothermic grassland (Fig. 3).