Volunteers? I mean the dactylorhizas seed themselves around.
I started out with four small white/pink orchids and five D. fuchsii 'Bressingham Bonus'. After a couple of years, I added one D. maculata and one D. majalis. All of these have mixed together, popping up new combinations all over the garden. I assume that all the shredded evergreen branches that I get from a tree trimming firm has sparked some fungal activity that these orchids love.
It's interesting that leaf forms range from all-over spots to pure green leaves. Flower colors range from almost pure white to dark mauve-y purple, with markings pale pink to very dark magenta.