Thursday, 18 June 2009

Dactylorhizal heaven

Last week we paid a visit to coastal Sussex to a min-flood-plain site that is home to a number of Dactylorhiza species that grow in profusion. For many reasons, I like the Dactylorhiza genus,the various species are usually stately and attractive plants and in Europe you are never far from one species or another, they can be found from the Mediterranean to the Arctic circle and the genus is represented in just about every habitat type. I do however often have problems with identification of many of the species mostly centred around the facts that firstly, Dactylorhiza is an essentially purple-flowered genus and superficially (the level of most of my plant identification), many of the flowers are similar and secondly, in many cases hybridization occurs between species often producing fertile offspring intermediate between the various parents.

At this site, there are three or four species depending on your choice of nomenclature, Common Spotted Orchid D.fuchsii, Southern Marsh Orchid D.praetermissa, and two Early Marsh Orchids D.incarnata (D.incarnata incarnata) and D.pulchella (D.incarnata pulchella).

As far as I am concerned, this number of Dactylorhiza species growing in the same place and such a small area (the entire site is no more than 400m x 100m) is quite unusual so perhaps given the circumstances it is not surprising that all sorts of strange things have happened (a bit like humans).

D.incarnata presents no problem of identification because the flowers are not purple but a wonderful flesh pink. The top picture shows a few flowers with typical markings and although the outer lip is not bent back something that is supposed to be fairly characteristic!

Having nailed this species, the direct comparison of flowers enables the identification of the other Early Marsh with some certainty, D.pulchella and splendid plants they were too up to 60cm high with intensely coloured flowers and dense spikes, real crackers (above right)!

Interestingly, at least I thought so, the two Early Marsh species tended to grow in separate patches as though their requirements were slightly different.

Moving on there were scattered plants of easily identifiable Common Spotteds D.fuchsii, typical colouring and the clearly indented lobe to the lip. But then there were many more plants that at a distance screamed Common Spot but when you looked closely were similar to the one on the left with an atypical lip shape but still with spotted leaves.

In addition, there were occasional plants that appeared to be pretty standard Southern Marsh Orchid (D.pratermissa) such as the one on the right and non-spotted leaves but then there were those with exactly the same flowers but spotted leaves and so it went on. After a while it became clear we were in the middle of a hybrid swarm, not as dangerous as a bee swarm unless you keep on insisting on identifying the individual plants. After a while you begin to doubt whether any of your identifications are correct, so take everything here with a pinch of salt!

Apparently this population has been the subject of a number of academic studies that I have not read (!) and it illustrates the problem of trying to identify individual species within genera that contain species are clearly not yet stabilized or whatever the correct term is.

In this case the simplest thing to do is sit back and enjoy the plants and the spectacle. A sheer joy!!

Wednesday, 10 June 2009

Old friends revisited

Box Hill, north of Dorking, Surrey, is a large area of mixed chalk turf, scrub and woodland renowned for its varied flora. It was where I was first shown how to identify wild flowers and felt privileged to be shown the rarities of the area. Since then (over 40 years ago!!!) I have visited the area regularly and at this time of year a walk almost anywhere is rather like going out to meet old friends.

We went for a stroll there the other night supposedly looking for Bee Orchid (Ophrys apifera) at a spot where there are generally plenty but very few this year, we only found a single plant. Now it could be a bit early for the Bee Orchid but I suspect not as at the same site we did find Musk Orchid (Herminium monorchis, right) just starting to flower, this must be two weeks earlier than usual, growing at the site I first saw it.

Across the road and there were a small number of plants of Deadly Nightshade (Atropa belladonna, left), within a few feet of where I first saw this species all those years ago.

We then moved on, not far, to a wooded area by the River Mole, to look for Turk's Cap Lily Lilium martagon at a site where, according to Lousley's Flora of Surrey, it has been known for little more than 50 years. Only one flower open as yet (below) and roughly the same number of plants as were present when I first saw them.

Finally we moved on to another site for the Lily about a mile away where it has been recorded for almost two hundred years , here also it was still in bud but the colony is huge with hundreds of plants spread over quite a large area. It will be a picture within a week or so when the flowers open, especially since there are a good number of white-flowered variants to add a bit of spice.

It is nice to meet old friends.

Thursday, 4 June 2009

White Orchid!

Our local Common Spotted Orchids (Dactylorhiza fuchsii) are just coming into flower at the moment and at one site, although only a small number of plants are present (1-200), the flowers are remarkably variable both in colour and in patterning. This year there is an addition, a single pure white spike has appeared. It does seem to be completely white with only the pollinia showing any colour at all, so I suppose it could qualify as var.albiflora, but if I did that I would have to come up with about 50 names for all the other colour variants present so I will just stick with "a white one".

This is the first time I have ever seen a white form of Common Spotted in forty years, despite it being supposedly common, so I was quite chuffed to find it locally especially as it is so attractive to look at.

Wednesday, 3 June 2009

Lemon Iris

At the moment, the local ponds are providing a fine display of Yellow Flag(Iris pseudacorus, left). This is a spectacular plant only spoiled by its very short flowering period. The golden yellow flowers brighten up even the dullest June day.

Even better, in this area we are lucky enough to be able to find the much paler lemon-yellow version (below) that goes under various names including the descriptive I.pseudacorus v.pallidiflava or less obvious v. bastardii. If anything this is even more beautiful than the type species appearing almost ethereal in comparison.

It seems to be a bit of a N.E.Surrey specialty occurring in a number of ponds around here although in Lousley's flora of Surrey it is only reported from a single site in Epsom. So far I have failed to find little details of it growing elsewhere.

The origin of this plant around here is something of a mystery. There is a pale variety that has been in cultivation since being introduced from the USA early in the 19th century but equally it was reported in the wild (not in Surrey) in the early 18th century by no less an authority than John Ray. It has also been recorded in Middlesex in the more recent past.

I would be interested to know if anyone out there has seen this plant elsewhere.