Dear Jay and group,
In Orchid Digest V6, #360, Jay Pfahl solicited ideas regarding the identity of several terrestrial orchid species, pictures of which were taken during travels through Brazil and Europe. The pictures taken at the Orkney Islands, UK, clearly showed species of the genus Dactylorhiza, and in a message to the Orchid Digest V6, #366, Jay let us know that Philippe identified these as all D. maculata, save one which he recognised as D. occitanica. However, there's no way that one of the plants that Jay saw at the Orkney's belongs to Dactylorhiza elata var. ambigua, of which, according to Pierre Delforge (in his 'Guide des Orchidies d'Europe, d'Afrique du Nord et du Proche-Orient', 2nd edition, Delachaux et Niestli SA, Lausanne / Paris 2001), D. occitanica is a synonym. Dactylorhiza elata proper is a species with a (sub)-Mediterranean distribution, with populations in Algeria, France, Morocco, Portugal, Spain and Tunisia, and the Mediterranean islands of Corsica (France) and Sardinia (Italy). The most northern and disjunct population ever, separated by more than 500 km (~ 315 miles) from the main area of distribution, was found in the Dutch province of Zeeland, in an area known as 'Zeeuws Vlaanderen' which borders Belgium. Here in the 1970's some 50 flowering plants could be found, as well as hybrids with Dactylorhiza praetermissa, but later, in the 1980's, the population dwindled and has now gone extinct. The province of Zeeland, which consists of several islands in a large delta, has relatively mild winters with only light frosts, which probably explains the occurrence of such a southern taxon.
To return to the subject, according to Delforge Dactylorhiza elata var.
ambigua itself ('D. occitanica') is restricted to a few departments of
mainland France (the Rhone basin, the Tarn and Herault and Alpes-Maritimes)
where it grows intermingled with individuals belonging to D. elata var.
elata. Given this distribution it is therefore highly unlikely that the
plants which Jay came across at the Orkney's (which are situated some 950
km [~ 600 miles] NNW of The Netherlands, and are separated by some
1400-1500 km [875-950 miles] from the main area of distribution of D.
elata) indeed belong to D. elata var. ambigua ('D. occitanica'). To which
species the plants that Jay saw do belong I do not know, and I am also not
sure whether the others indeed are Dactylorhiza maculata as Philippe
claims. The individuals with spotted leaves shown in some of the photos
could well be, but Dactylorhiza incarnata very occasionally shows leaf
spotting too! and Dactylorhiza majalis is another option... But, what about
the individuals with unspotted leaves?A few additional remarks. As I have written before some time ago, one should be very careful identifying orchids (plants) from pictures, especially so when these are lacking in pertinent details (length of spurs relative to length of ovary, length and stance of ground leaves, length and position of bracts along the inflorescence etc. etc.) and when these are taken in areas the flora of which one is not well acquainted with. Plants vary, not only at a regional level but also at population level, and to this it should be added, as is appropriate in this particular case, that the genus Dactylorhiza belongs to a taxonomist's worst nightmares. For various reasons there is still a lot of confusion about the exact species boundaries within this genus (the species count hence varies from ~22 to ~ 80, depending on whom you ask), and added to this comes the fact that several species easily hybridise in several directions, resulting in local hybrid swarms which phenotypically vary according to the location. It appears that especially in Northwestern Europe and the Alps this genus is going through a stage of active evolution and adaptive radiation, which may well be in response to rapidly changing environmental conditions. Not only do populations show a strong tendency to form local ecotypes (which in some cases, with only some 20-30 km in between them, may look like they're entirely different species), it has also been shown that stable species have arisen as a result of hybridisation (and in some cases hybridisation followed by subsequent chromosome doubling) or by autotetraploidisation. In several cases these 'derived' species and forms inhabit narrowly delimited habitats from which other members of the genus are absent. Dactylorhiza sphagnicola for instance, which inhabits ultra-acid raised sphagnum bogs in northwestern Europe in which no other dactylorhizas occur, is proven to be a tetraploid hybrid of Dactylorhiza fuchsii and D. incarnata, while the Eurosiberian D. maculata seems to be a stabilised autotetraploid of D. fuchsii. With so many hybrids and local forms around, the result of all this is that, speaking for myself, I often fail to reliably assign species epithets to particular plants and, vice versa, species which I have learned to recognise in The Netherlands may in neighbouring countries at distances of only 150-200 km appear so much different that a species name can be assigned to them with only the greatest difficulty. It is because of all this that I often think it to be funny when yet another tropical species has been described because of a slightly different staminode or oddly twisted sepals or whatever. Plant species vary, as do we, and therefore one has to be careful when assigning names, especially so when all that is at hand is a picture.
However, should you wish to have a 'second opinion' with respect to your pictures taken at the Orkney's, I kindly suggest that you contact Mr Carel A.J. Kreutz. Mr Kreutz is the author of several stunningly beautiful and informative books on the Orchidaceae and Orobanchaceae (!) of (various parts) of Europe and Turkey, and is one of the leading specialists on the orchid flora of Europe. His e-mail adres is [EMAIL PROTECTED]
Hoping this helps,
Simon M. Wellinga / SymPhyto - Laboratory for in vitro plant propagation Heerenveen The Netherlands / EU _______________________________________________ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
