D. cambrensis is a marsh orchid first described from Wales in 1961 and known by several synonyms which variously ascribe it full species, sub species or simple varietal status.

This is a taxon whose range isn't fully understood, not least because of its geographically similar distribution and morphological resemblance to D. purpurella. An additional complication, common when attempting to distinguish many Dactylorhiza species, is that of hybridization and perhaps more relevantly, gene introgression over many years. The distribution of D. cambrensis is centred on the north and west coast of Wales but is also reported from the north of both England and Scotland, though these non Welsh populations are treated with a degree of circumspection by some authorities.

This species is seldom found far from the sea, damp slacks within coastal sand dunes being very much its preferred habitat choice. In these situations it's often found growing alongside its close relative D. purpurella, a species which at first sight can be remarkably similar but one where differences can be detected on closer inspection. D. cambrensis is typically a more robust plant with an inflorescence comprised of a larger number of tightly packed flowers which are noticeably paler than the deep  magenta colouration of D. purpurella. The flowers also differ in lip shape, being distinctly tri-lobed as opposed to the diamond shape of D. purpurella. Leaf markings are also a useful indicator with D. cambrensis usually exhibiting strong spotting and/or characteristic dark rings. This feature is however diagnostically unreliable as D. purpurella can also be spotted and conversely D. cambrensis unmarked.