Heath Spotted Orchid - Dactylorhiza maculata
This is the spotted orchid that favours the neutral to slightly acid soils prevalent in upland areas. Confusion with Dactylorhiza fuchsii is a frequent occurrence; they both have similarly spotted leaves and the flower colours are likewise similar. Dactylorhiza maculata however has a much smaller central lobe to the labellum, and the side lobes are larger with round outlines. The markings are rarely as bold as can be seen on Dactylorhiza fuchsii The likeness between the two species is easily explained. The Heath Spotted Orchid clearly has a preference for more acid soils and heathland.Dactylorhiza maculata is an autotetraploid (2n=80) with all its genetic make-up coming from Dactylorhiza fuchsii.

The text books tell us that Dactylorhiza maculata is represented in Britain and Ireland by sub-species ericetorum. However some of the same books can also tell us that sub-species maculata and elodes, both normally continental in distribution, can be found here. To me however, the differences seem rather minor and subjective. But I will trust the authors that the sub-species do exist- with one exception. Some authors consider there to be one species of Spotted Orchid and refer to the Common Spotted as Dactylorhiza maculata ssp fuchsii. This does not make taxonomic sense to me, putting the parent species as a sub-species of the child species. This is because over the water they do not see the same division of morphology between the two species. The two species of Spotted Orchid are sufficiently different by both plastid haplotypes and ITS types to be counted as separate species, in addition to their preferring different habitats. That, however, did not prevent some samples in a large study to have a D. fuchsii morphology and yet have D. maculata genetic make-up - and vice versa.

There is a suggestion that D. maculata, being an older polyploid species, arose from a polyploid event somewhere in North Africa before 20,000 BP. The genetics are very similar to D. foliosa, a Madeiran endemic. North Africa and Iberia harbour further subtly different, in terms of both morphology and genetics, forms of D. maculata. This compares with the situation in central Europe. A North African alloploid species, D. elata, seems to have D. maculata as the maternal ancestral parent.
What I cannot quite get my head around, is that while the maculata complex invariably has ITS I, the plastid haplotypes vary widely. The same one can be found in Iceland, Spain, Sweden, Wales. and England. However, other haplotypes can be found in Ireland, Norway, Portugal, and Wales. These may be just one DNA base changes acquired over the millennia. However why does D. maculata have ITS I, while D. fuchsii, its paternal and maternal diploid ancestor, have a mix of ITS III and V? The answer must lie in the ancestry, but does seem to rule out multiple polyploid events giving rise to the many forms of D. maculata.

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