P. crystallina subsp. hirtiflora from Roya Valley an introduced population or not ?
or P. longifolia var. reichenbachiana on the way of an diseapering ?
Jurg Steiger : INTRODUCED !
He feels that this population can't be natural because, it is so far from the other populations and there is so many hundreds kilometres to go. His opinion is shared by other botanists. Who introduced seeds or plants there ? What was the reason for this ?
As you know, Pinguicula longifolia subsp. reichenbachiana grows very close to this introduced population but we didn't note any hybrids.
Filippo Tassara (pers. email on 2nd May 2006) : INTRODUCED !
Considering the situation as it appears now, we can't be certain of the origin of those plants.But we can consider the possibilities of a natural occurrence of P. crystallina there. And they are very low, against very high possibilities of an introduced plant. First of all there are no historic data about P. hirtiflora in Roya Valley. P. longifolia var. reichenbachiana is known from more than 100 (150?) years, and it had been continuously visited by many botanists who never reported any P. hirtiflora there.
Second, P. reichenbachiana is surely there from a very long time, probably from the end of the ice era (10-15000 years ago), when it should be quite widespread from there to Apuane Alps, probably more common than today. In this long time P. reichenbachiana reached every corner of the Roya site where it could live and there it is.
P. hirtiflora grows in a well defined spot and in the other parts of the site is absent. Completely. I would expect that a plant not perfectly suited to that habitat due to low temperatures of the past would be maybe represented by few specimens, but well distributed all over the site. It is very unlikely that a few plants remained localized in a confined spot for more than 10000 years without disappearing and without colonizing the entire site. It is not a stable condition. About the recent temperature changes, I don't think they could influence much the P. hirtiflora population. The miroclimate there seems very stable, and in the summer it appreciates low themperatures more than high ones.
In the winter there has not been an increasing in temperature in the last years. Also, an hybridogen origin of P. crystallina is possible, but the colonization of S. Italy and Greece must be very ancient, probably related to the ice eras. And in the eastern area it developed different forms, which probably took a very long time (thousands and thousands of years). And the hybridization didn't surely happen among one of the todays forms of the plants, but among prehistoric forms today surely extinct or changed.
Moreover, if I planted a single P. hirtiflora specimen in a P. vallisneriifolia site I would expect in a few decades exactely the same evolution it had in Roya Valley. Also a recent natural (by birds or so on) transfer of the species to Roya Valley is quite impossible, compared to a human introduction, which would be very simple to do.
If I should give numbers, I'd say there are 99,99% possibilities of an human introduction against 0,01% (or less) possibilities of a natural occurrence. It is important to consider the 0,01% possibility, but I find unreasonable to almost completely ignore the 99,99% other probabilities.
P. hirtiflora seems very aggressive aginst P. longiflolia, and I think we will lose the latter in a quite short time. No chances for a P. longifolia seedling to grow among P. hirtiflora plants. P. hirtiflora is quickly popping up everywhere, where it was not a few years ago.
The Mercantour Park protected the population with a fence against curious people, but doesn't realize the worse potential danger is inside the fence!
I don't know of other Pinguicula species requiring the same environment occurring together in the same site. It is likely one will outcompete the other.