A Northumberland Alpine Gardener's Diary
This entry: 23 May 2009 by John Richards
Some plants from southern chalk. Entry 116.
Note from the Auricle
I have Sidney Clarke to thank for the following information. Sidney was formerly photographer at the Royal Botanic Garden Edinburgh, and is perhaps best known in alpine circles for his fine book on Scottish orchids. However, he is also a considerable authority on European primulas, having visited most of them to take his superb photos.
I take some blame for the following, although the fault did not originally lie with me. Over the last two or three years, I have been assiduous in promulgating the message that what was formerly known as Primula auricula in reality consists of two species, from the north and south of the Alps. So much remains true. However, the original publications by the authors of this work, Zhang and Kadereit identified the Linnaean species P. auricula with the northern species. Consequently, it was thought that the southern species required a new name, for which the combination P. balbisii was prior, and this was the message I have been spreading, in these pages and elsewhere.
Sadly, subsequently I have not followed the literature as assiduously as I might. In a later publication, Zhang and Kadereit say that they were wrong, and the Linnaean type is the southern plant. In that case, what we were calling P. balbisii (also the old 'albocincta') becomes P. auricula, and the northern plant requires a new name, for which the prior combination is apparently P. lutea. I have not myself checked the identity of the Linnaean type, but this correction must have been even more painful for Zhang and Kadereit than it has been for me, so I think we can assume it is correct.
Trans-species miscegenation shock! Monkeys mate wi
We have recently returned from one of our periodical visits south to visit family. It seemed to me that the timing was right to visit the Hartslock Reserve near Goring, famous for its rare orchids. I have known this site since childhood. In those days, the monkey orchid, Orchis simia had become very rare, and I believe the population became reduced to seven plants. What was the main, lower slope, had been ploughed during the war years, and only a few individuals survived on the steeper upper slope, which now holds the main population. In the 1950's and 1960's the plants were covered by cut gorse to save them from prying eyes, and the location was a well-kept secret. This did little for their pollination, seed dispersal or photosynthesis, but slowly the population has started to flourish.
The location is now openly publicised; indeed it has its own website which records the numbers of individuals. There are now more than 500 plants of monkey orchid, and it has started to recolonise the original site, the lower slope, again. Even more interesting, perhaps, has been the arrival of the Lady Orchid, O. purpurea, and its subsequent hybridisation with the Monkey Orchids. When I last visited, about eight years ago, there were two Lady Orchids. As far as is known these had arrived unheralded, presumably by air-borne seed. The main English sites were in Kent, far distant, although there is one other small Chiltern site for Lady Orchid, but this is also far removed from Hartslock.
Last week I could still find only two Lady Orchids, although the website says there are eight. Here is one of them.
Even more startling are the hybrids. These surround the Lady Orchids, and show obvious hybrid vigour, being noticeably taller than either of the parents. Although they are clearly these hybrids, they closely resemble another rare English species, the Soldier or Military Orchid, O. militaris, which might I suppose give some clue as to how the latter species evolved. In fact, if these plants had been found in another context, without the parents, it would have been difficult not to name them O. militaris. I saw about 20 obvious hybrids. The website says there are now no less than 130 of them, which is difficult to believe, unless many occur in a different part of the Reserve away from general access. Here are some pictures of the hybrids.
Here are some pictures of the other parent to the cross, the Monkey Orchid. This is one of only two English stations for this species now, although it occurred in Yorkshire until quite recently.
This is a beautiful part of the country. Here is the view westwards up the Thames as it forms the 'Goring Gap'. Brunel's elegant railway bridge can be seen in the distance.
The orchids are by no means the only interesting plants at Hartslock. Of some interest to the alpine gardener is the Chalk Milkwort, Polygala calcarea, well-known on rock gardens in its Pyrenean form 'Lillet'. It looks as if the English plants might also make attractive plants, although they should definitely be left where they are!
Later the same afternoon I crossed the river to the Berkshire side and investigated the downs above Streatley. Here I was delighted to find another very scarce plant; indeed one I had never seen before, the Early Gentian, Gentianella anglica. This is a close relative of the familiar annual felwort, G. amarella, but flowers much earlier and is a dwarfer plant.
Here too, on Lardon Chase were great carpets of Horseshoe Vetch, Hippocrepis comosa. This rather uncommon southern chalk plant is very significant as it is the only foodplant of two iconic butterflies, the Chalkhill Blue and the Adonis Blue, which are thereby limited by the scarcity of the hippocrepis. When these butterflies fly, later in the summer, the vetch can be very hard to find here, but in flower, as it is now, it is very conspicuous .
Not much to note from the garden at present, but the big blue poppies came into flower during our absence. We grow seven varieties of M. x sheldonii, as well as one each of M. betonicifolia and the true M. grandis. Here is 'Sieive Donard', I think.
I showed M. aculeata starting to flower in the last entry, but several more have flowered subsequently, and one was bluer than the general amethyst hue.
Lovely things, but it is hard to beat Jancaea heldreichii, possibly my favourite alpine (strong competitors are Meconopsis delavayi and Paraquilegia anemonoides, so you see what I really like! - a touch the the blues! In fact I have flowered all three this year so I am in seventh heaven!).
I grew and flowered jancaea more than 20 years ago, but lost it and have not had it at the present house until now. A few years ago I acquired a small rooted scrap from Ger Beukelen, inserted it into the north side of home-made tufa in the alpine house, with a trickle water feed in the summer, and it has not looked back, flowering now for the first time.
To finish with, two reliable plants for outside. Saxifraga continentalis is winter-green and summer dormant, flowering as it dies down for the summer. This does not always make for the most attractive plant, but it is easy, even invasive, seedings and rapidly growing to form a large mat. It may not be everyone's cup of tea, but I like it.
Three or four tulip species are persistent here outside, even increasing. Earlier, these include T.praestans, T. uruminensis and T. aucheriana, and now T. saxatilis and T. batalinii are flowering. T. sprengeri is even later, flowering into June. Here is T. batalinii, holding its own in a wild part of the garden.