Devillers, P. & Devillers-Terschuren, J.A. 2000. Dactylorhiza sudetica in the Giant Mountains. Extended summary. Royal Belgian Institute of Natural Sciences website, www.naturalsciences.net/cb. [Original published in French in Natural. Belges 81 (Orchid. 13)].
Dactylorhiza sudetica is a long-known taxon, described by Reichenbach in1851 on the basis of a type taken in the Sudeten, a biogeographically remarkable Hercynian range located astride the present Polish-Czech border. The epithet has been used erratically to designate both Alpine and Fenno-Scandian taxa. At the same time, Sudetic populations were often designated locally by names borrowed from the Scandinavian flora, such as D. psychrophila. These vagaries probably reflect the unique character of the high-altitude ecosystems of the Sudeten, formed of both arctic and Alpine elements accompanied by an impressive endemic cortège. Confusion over Dactylorhiza sudetica seems to persist in spite of detailed studies conducted in Central Europe. The most frequent present-day usage is to employ D. sudetica for the Alpine populations described by Tyteca & Gathoye (1990b) under the name of Dactylorhiza savogiensis, and to call the Sudeten populations Dactylorhiza fuchsii ssp. psychrophila or Dactylorhiza psychrophila. Having seen D. sudetica in its habitat, with a field experience of some of the Scandinavian and Alpine taxa with which it is often associated, we review the characters of the Hercynian species and express our conviction that there is no reason to link it to another taxon, Scandinavian or Alpine.
A small station of Dactylorhiza sudetica was visited in the Giant Mountains (Krkonose/Karkonosze, Sudeten), on 27-28 July 1999. These mountains, reaching an altitude of 1602 m under a severe climate that results from their position as the first barrier to the north and north-easterly winds sweeping across the Baltic Plain, with the softened topography of an ancient relief, have retained an extensive arctic-alpine zone above the timberline, at 1250 m, some 350 m lower than in the Tatras. This extrasylvatic mantle has had a continuous existence throughout the post-glacial period and harbours extremely isolated communities. The vegetation of the range is dominated, in the montane zone, by beech forests of the Dentario enneaphylli-Fagetum, Luzulo nemorosae-Fagetum and Calamagrostio villosae-Fagetum. In the sub-alpine zone there is a spruce belt, particularly natural and characteristic at the approach to the tree limit. Above the tree limit there are two unique habitat complexes. On well drained soils, in particular, on slopes, summits, glacial cirques, thickets of mugo pine (Myrtillo-Pinetum mugi, Pinetum mugi sudeticum) are associated with silicicolous alpine grasslands dominated by Nardus stricta, Festuca airoides, Juncus trifidus or Carex bigelowii ssp. rigida, with occasional snow-patch formations. Great peatbogs form a second mosaic. Buttes carry thickets of Pinus mugo associated with Rubus chamaemorus, the only place where the Alpine pine and the arctic cloubberry come into contact, or carpets of Trichophorum caespitosum and Polytrichum. Depressions have bog or mire lawns mainly dominated by Carex rostrata, Eriophorum angustifolium or Eriophorum vaginatum. Near the bogs are Nardus grasslands, subalpine tall-herb communities with Adenostyles alliaria and Aconitum firmum, associated with tall-grass formations of Calamagrostis or Deschampsia cespitosa and subalpine thickets with Salix lapponum, Salix silesiaca and Betula carpatica, spring communities and small formations of basicline infra-aquatic mires with Swertia (Bartsio-Caricetum nigrae).
The Dactylorhiza sudetica colony that we saw is located at 1420 m altitude, in a terraced slope that joins one of the large bogs of the plateau to a deeply cut glacial cirque. It is situated in a complex of humid grasslands of the Carici fyllae-Nardetum and tall-herb stands of the Cicerbito alpinae-Adenostyletum alliariae, Petasitetum albi and Bistorto-Deschampsietum alpicolae, associated with spring communities comprising Epilobium alsinifolium and Stellaria alsine. The plants are located on a bank, in a humid grassland dominated by Molinia caerulea with, notably, Nardus stricta, Anthoxanthum odoratum, Carex nigra, Phragmites australis, Trientalis europaea. This commmunity is probably allied to that described by Jenik et al. (1980) for a similar cirque of the Jesenik, in the eastern Sudeten, as Violo biflorae-Molinietum. Associated with the orchids was a plant of Pedicularis sudetica. This species is itself endemic to the Giant Mountains (Fabiszewski 1993; Stepankova et al. 1995; Krukowski 1997), its closest allies being distributed in the Arctic regions of Eurasia, from the eastern Kola peninsula eastwards, and in North America. The similarity between Dactylorhiza sudetica and Pedicularis sudetica is striking and, in view of the strategies for pollen production avoidance displayed by both genera (Proctor et al. 1996), one may wonder whether their association is fortuitious, and, if not, who imitates whom.
Dactylorhiza sudetica was described, illustrated and compared to other taxa of the group of D. maculata by Jagiello (1988). She characterized the plant as small, no taller than 25 cm, with 3-5 ovoid-oblong leaves, a short inflorescence and small flowers, with a lip averaging 6.6 mm long and 8.7 mm wide. The lip index, calculated by Heslop-Harrison's (1954) formula, 2A/(B+C), where A, B, C are the distances, measured parallel to the axis of the lip, between the base of the labellum and the tip of the central lobe, the tip of the lateral lobe and the summit of the sinus, respectively, is 1.30 on average, comprised between the indices of the 11 D. maculata populations that she examined, for which it varies between 1.12 and 1.29 (average 1.20), and those of the 19 populations of D. fuchsii that she measured, comprised between 1.39 and 1.67 (average 1.50).
Our observations confirm the diagnoses of Jagiello (1988). Plants of D. sudetica appeared to us as small and delicate, with short inflorescences and small leaves with a characteristic oblong to spatulate shape. The flowers are small and variable in shape, but the lip has a central lobe that is always well marked and protuberant, even if generally narrower than the lateral lobes, with which it sometimes joins to form a nearly rhomboidal lip. Lip shape in the plants we have seen, as in the photos of specimens published by Jagiello (1988), reminds us more of D. fuchsii than D. maculata. The pattern of lines on the lip is fairly continuous, wide and well marked, purple on a pale to bright pink background. It is more evocative of the design on the lip of D. fuchsii than of that seen in most populations of D. maculata. Dactylorhiza sudetica presents characters intermediate between those of lowland and hill populations of middle Europe that can be attached either to D. fuchsii or to D. maculata and its allies, including D. ericetorum and D. elodes, a particularity shared with some of the alpine and northern plants with which an affiliation has sometimes been proposed.
The Alpine plants were described by Tyteca & Gathoye (1990b) under the name of D. savogiensis. Later, Tyteca & Gathoye (1991) proposed to place this name in the synonymy of D. sudetica, a step followed notably by Delforge (1994), Quentin (1995) and Bournérias et al. (1998), but questioned, rightly, by Gölz & Reinhard (1997) and Schmid (1998). D. savogiensis is a distinct and valid species that does not show any marked resemblance with D. sudetica. The photos published by Gathoye (in Tyteca & Gathoye 1990b), Delforge (1994), Tyteca (in Bournérias et al. 1998), those that we have taken at the col de la Madeleine in July 1984, and the descriptions by Tyteca & Gathoye (1990a, 1990b), and Gölz & Reinhard (1997, 1998) show that D. savogiensis is a fairly robust plant with an elongated, multiflorous inflorescence, narrow, lanceolate, sharply pointed leaves, large flowers with an ample lip recalling that of D. maculata, with a generally saturated color giving little contrast between background and design. These characters contrast strongly with the often short and relatively pauciflorous inflorescence, the oblong obtuse leaves, the small, pale-coloured flowers with a very contrasted design and a prominent central lobe of D. sudetica.
The far northern plants, to which the name Dactylorhiza kolaensis applies, well described and illustrated by Delforge (1990, sub nom. D. montellii; 1994), and that we have seen in good numbers at the North Cape in July 1997, are a little more similar to D. sudetica, in particular by their gracility, the reduced number of flowers and the small size of the inflorescence, the small size and the pale colour of the flowers. The inflorescence is somewhat more pauciflorous than in D. sudetica, the lip design on average a little less marked and more fragmented. Mostly, the leaves of D. kolaensis are much narrower and more lanceolate than those of D. sudetica and the flowers much more ample, more circular, nearer to those of D. maculata and its allies.
Dactylorhiza psychrophila is described from Fenno-Scandia, the neotype coming from Muonia, in northwestern Finland, near 68° N (Vermeulen 1947, Averyanov 1982). Its range includes northern Europe and northwestern Siberia (Hennecke 1993). Its delimitation with respect to D. kolaensis is not entirely clear. The very scanty information that exists (Vermeulen 1947, Averyanov 1982; Hennecke 1993; Delforge 1994), in so far as it applies to a single taxon, indicates a plant whose flowers, small and few, display in an extreme way the characters of D. fuchsii. It does not seem to look more like D. sudetica than does D. kolaensis. It seems to be diploid (Hennecke 1993), while D. sudetica may be tetraploid (Jagiełło 1988; Jagiełło & Lankosz-Mróz 1988). The name D. psychrophila was used, probably wrongly, to designate Hercynian populations of Central Europe (Holub 1964; Heinrich 1997), among which D. sudetica, as well as Alpine populations, notably in France and Austria. The latter, illustrated notably by Gerbaut (in Bournérias et al. 1998) and Klein & Kerschbaumsteiner (1996), do not resemble D. sudetica -- nor, probably, are they related to D. psychrophila.
Given our present state of knowledge, Dactylorhiza sudetica should be considered as a very original species, endemic to the Giant Mountains. If it is shown to be tetraploid as indicated by Jagiełło (1988) and Jagiełło & Lankosz-Mróz (1988), it is probable that it appeared as the result of a local autopolyploidy event. If morphological resemblances must be found, they should be sought in the arctic taxa D. kolaensis and D. psychrophila, not in the Alpine ones. D. savogiensis, in particular, should not be attached to nor even placed near the Sudeten species. It is possible that other dactylorhizas of the upper levels of the major Hercynian mountains, in particular the Erzgebirge and the Thüringer Wald (Heinrich 1997), are conspecific with D. sudetica. However, Gölz & Reinhard's (1994) suggestion of a chaotic character in morphological variation of orchids, though probably not very applicable to genera Ophrys and Epipactis, might apply rather well to genus Dactylorhiza and its very open mode of pollination. In that case, the principles that underpin the phylogenitic species concept, evolutive isolation and plateau of diagnosable morphological variability, would be the only ones usable and should be carefully considered before arbitrarily regrouping populations belonging to biogeographically and ecologically distinct ensembles.
Dactylorhiza sudetica appears to be an uncommon species, limited to few stations with small numbers of individuals. Its distribution is probably similar to that of Pedicularis sudetica for which Krukowski (1997) has documented present-day scarcity, considerable recent decrease and strong sensitivity to habitat degradation, particularly that induced by atmospheric pollution. D. sudetica should thus be considered a fragile species and be placed on the list of target species to be taken into account in the management plans of the transborder biosphere reserve that encompasses the Krkonose and Karkonosze national parks.
Key-words: Orchidaceae, genus Dactylorhiza, Dactylorhiza sudetica, Czech Republic, Hercynian ranges, Sudetic Mountains, Sudeten, Krkonose, Karkonosze, Giant Mountains, Riesengebirge.