Presser (2000) states also that the species grows in the Alps in particular at locations whit a high level of precipitation where snowcover is persistent in late spring. It is not clear on which observations this statement is based.
* Delforge regards the plants of the province Cuenca in Spain, a location already known by Landwehr (1977), as a separate species named Orchis cazorliensis. Marijke Verhagen and Jan van der Straaten, searched for this species in the Serrania de Cuenca, mentioned by Landwehr as a location of this species. To their surprise they found some flowering plants on the Puerto de Monsaete at an altitude of 1150 meter in May 2002. This location is very similar with the bare slopes high up in the Vercors. In the Serrania de Cuenca the plants were growing on a vegetationless south-eastern slope. The substrate was quite identical from that in the Vercors. The climate on this location undergoes strong continental influences with low temperatures and substantial snowfall in winter.
The flowers in Spain were somewhat lighter coloured than those in the Vercors, which was partly caused by the fact that the Spanish flowers nearly finished flowering. Comparing the pictures from Majadas, some ten kilometres away from our location, with those from Thorence in France as they are published in the Landwehr publication (2000, p. 254), we could not discover significant differences. Nevertheless, the flowers in the Vercors are darker than those from Spanish locations. Furthermore, when one studies the different pictures from the French Alps in the Presser publication (2000), it is striking that even in such a small area flowers can be either dark or light. Additionally, we compared our pictures from the Vercors with the Spanish flowers and the pictures in the Bourn�rias publication (1998). By doing so, we came to the conclusion that the Spanish flowers are not greener than the French plants, as is stated by Delforge; on the contrary. Finally, we were not able to find significant differences between the plants in the Vercors and those from the Puerto de Monsaete. Therefore, we cannot see the rational in separating the plants from Spain from Orchis spitzelii. Furthermore, our knowledge of Orchis spitzelii and its growing requirements is still so limited, that it would be a better option to study these problems than starting to �discover� a new species.
species of Orchis spitzelii. From our data it becomes clear that Arctostaphyllos uva-ursi is only an accompanying species on locations which are situated on steep and stony slopes. This is only a very limited number of the locations. From our data the conclusion can be drawn that Delforge bases his general conclusion on a too low number of specific situations, which do not allow general conclusions.
*In the distribution-atlas of the departement Is�re (Mus�um d� Histoire Naturelle de Grenoble, 1995) Cypripedium calceolos is mentioned as an accompanying orchid species for Orchis spitzelii. There is no location in the south-eastern Vercors, which justify this statement. Cypripedium is growing at completely different situations: the biotope is wetter, richer in nutrients and Cypripedium grows very often in shadow-rich situations. Cypripedium is quite often found on slopes in the Vercors, but never in the neighbourhood of Orchis spitzelii. It could be the case that the two species are growing together in Wallis, where Lauber and Wagner (1996) mention a forest of Fagus sylvatica as a location of Orchis spitzelii. Additionally, the description of Lauber and Wagner is not clear, as in the original publication on this location (Hertel, 1988) an open steep slope at an altitude of 1950 meter is mentioned, where Fagus sylvatica is completely lacking. The description of Hertel is quite similar with our location 24.
* Landwehr (1977) mentions that the species is in particular growing on northern slopes. It seems that this statement is based on Spanish locations, which he knew quite well. In the south-eastern Vercors Orchis spitzelii is absent from northern slopes. Only in two cases a northern inclination could be recognised. However, in these cases the slope was not steep and these open location were therefore in the sun in spring and early summer. In the Vercors no locations were found on real northern slopes. Presumably, the effect of the sun in spring and early summer is necessary for a good development of the plants.
Locations in the Vercors
From the table some general conclusions are apparent. All locations, with the exception of two, are situated on a southern or a south-western slope. The lowest location is at 975 meter, while the highest is situated at 1750 meter. There is no relationship between the altitude of the location and the numbers of plants. The richest locations are on the lowest and on the highest locations. Further on, we will pay attention to this curious phenomenon.
We found 14 orchid species as an accompanying species: Dactylorhiza sambucina, Dactylorhiza fuchsii, Orchis purpurea, Aceras anthropophorum, Cephalanthera damasonium, Cephalanthera rubra, Ophrys insectifera, Orchis mascula, Orchis ustulata, Neottia nidus-avis, Listera ovata, Gymnadenia conopsea, Platanthera bifolia and Cephalanthera longifolia. One would be inclined to value this as a high number of accompanying orchid-species; one should not overlook, however, that the Vercors is very rich in orchids. The general tendency is that the locations of Orchis spitzelii are found in areas, which are relatively poor in orchids. Furthermore, the dimension of the location plays a role. On the richest location the Orchis spitzelii plants are growing on many parts of a vast slope. When one wants to determine in this vast area all accompanying species, this number is ipso facto always higher than on a location where only a few plants are found. There are 13 locations where one or more orchid species could be recognised, while on 29 locations no orchid species where in the neighbourhood.
It is not easy to determine the general characteristics of Orchis spitzelii locations in the Vercors. In fact, there are three types of locations: slopes with sparse vegetation, the fringes of the forest, and finally the open forest. In all cases the substrate is poor in nutrients. There are 33 locations where Orchis spitzelii grows in or at the fringes of the forest; in 27 cases this was a Pinus nigra or Pinus sylvestris forest, while in only 6 locations the forest was a Fagus sylvatica one. In the Vercors Pinus nigra and Pinus sylvestris are growing on dry slopes with low levels of nutrients in a thin humus layer, while Fagus sylvatica is growing on the wetter slopes which are richer in nutrients. In these open forests with a low input of nutrients the vegetation is open.