A Northumberland Alpine Gardener's Diary
This entry: 23 July 2013 by John Richards
French Alps 2. Entry 249. Ranunculaceae etc.
Pulsatillas in France
Nearly three weeks since we returned from France, and I haven't finished editing and labelling the photographs yet. We had a (very hot!!) week in the south visiting relatives. I was very worried about leaving the plants in such a hot dry spell and large numbers were moved out of the alpine house and under bushes etc in deep shade. On the whole this seems to have done the trick and few of the older plants seemed to have suffered unduly. Yesterday, in cooler cloudy weather I moved them all back again into the plunges under glass and am now rater regretting having done so, as the promised thunderstorms have missedus and its hot and sunny again. Out with the hose again this evening I suppose!
Anyway, I escaped into the office this morning and edited a lot more photos. This led to quite a lot of research ('wasted time', my conscience keeps grumbling!) particularly about the classification of the alpina group of Pulsatillas in the western Alps. Doubtless, if I get around to buying the new (limited edition) Pulsatilla book by Kit Grey-Wilson, all will be revealed, but as it is my researches on the Net have been less than revealing.
In the south-west Alps, one is in the zone for P. alpina ssp. alpicola, the new name for P. alba, as a result of research by D M Moser who has shown that it differs from type P. alpina no more than other segregates. This is a relatively small plant with flat leaf segments which are without hairs above. We found extensive populations of such plants on all three of the passes south of Barcelonette, usually on relatively acidic ground, growing for instance among bilberries. Here are two pictures fron the top of the Col de Cayolle.
Incidentally, P. a. alpicola often grew with the superficially rather similar Anemone baldensis. This came as a surprise as I had always thought of the latter as a limestone plant, and we later saw it on this substrate on, for instance, Col de Galibier and Col de Petit Mont Cenis. However, the Mercantour Passes are geologically complex and such plants as Dryas are often found growing with undoubted calcifuges such as Rhododendrom ferrugineum. Here are two shots of the Anemone from the Allos Pass.
Moving on with the discussion on Pulsatillas, lets get P. alpina ssp. alpina out of the way. This (the white flowered widespread subspecies) is supposed to be typical of alkaline ground, and we saw it in all the sites we visited, usually still in flower in this delayed season. We only once saw a plant even slightly sulphur in hue, on the Col de Var, and even this was surrounded by white ones. Rather than say how it is distinct, I shall wait until the two later taxa. These pictures are from the Col de Galibier where it is abundant and magnificent (as it is on lower Lautaret as well).
In the western Alps, Moser has delineated two other subspecies of P. alpina (others are also known from the southern and eastern Alps). I am more comfortable with P. alpina ssp. millefoliata. This is distinguished by having very large numbers of achenes (and large untidy fruiting heads), and highly dissected leaves which when fully mature grow to a great size. In flower I think the large achene (gynoecium) number is the best character and I was happy that wonderful plants on the Col de Petit Mont Cenis corresponded to this taxon.
Note the huge bosses in the centre of the flower. This is what we are talking about.
The other taxon is P. alpina subspecies cottianaea, which was described from the Italian side of Mont Cenis, but which is more widespread although localised to the west-central Alps. I have found it hard to discover the distinctive features of this taxon, but believe that the markedly pinnate leaves, and glabrous outside of the flower are distinctive. There is some suggestion that, nevertheless, it may be a very hairy plant when young. Also, plants I thought might be this seem to have notably blue backs to the perianth, but I am not sure if this is relevant.
I did wonder if some distinctive plants we saw on Galibier (close to 'normal' alpina) might have been cottinaea.
Before leaving Pulsatilla, I have to mention P. vernalis, one of my very favourite plants. This is a very early plant, and was over on Col de Var, and Col de Restefond. However, it was in good form in parts of Col de Galibier, and on the Col de Petit Mont Cenis we saw it growing with one of my main quarries, the local Primula pedemontana.
I had mentioned Anemone baldensis, but this pales into insignificance in comparison with the splendours of Anemone narcissiflora. Local in most of the Alps, this is quite common in the Mercantour, Mont Cenis, and especially in the Lautaret meadows where it competes with Narcissus poeticus, the pheasant's eye.
One of the great thrills of the trip was to find a good population of Callianthemum coriandrifolium at one location on the Col de Galibier, where I am sure it is known to many people, as it is just along an obvious stroll onto a limestone pinnacle close to the road. A few years ago, we found C. kernianum on M. Baldo, but I thought C. coriandrifolium by far the finer plant.
I showed a picture of Aquilegia alpina in the last entry, so I shall pass on to the final Ranunculaceous genus I intend to discuss here, Ranunculus itself, confining myself to the white flowered species. On this occasion we failed to find R. seguirii, which is reported from Galibier, and also from the Restefond (possibly inaccurately, as we saw a lot of white flowered R. glacialis there). The Col de Restefond is the highest road pass in Europe, and R. glacialis grows beside the road in wet rock debris at over 2700 m, but we also saw it much lower, at scarcely over 2100 m, in quantity where a stream flowered under the road.
My final discussion concerns two closely related white buttercups which are abundant early in the season on high wet ground. These were originally known as Ranunculus pyrenaeus and R. p. ssp. plantagineus. The latter, more robust plant with wider plaves has since been elevated to specific rank as R. keupferi, but I am not convinced that this is a good thing, as the two can be often hard to tell apart. On the Mercantour passes in particular, all gradations of robustness can be found. Here on the Col de Allos are what I consider to be typical keupferi.
And here, high on Galibier, what I consider to be the true R. pyrenaeus, just like the plants in the Pyrenees.