I'm not exactly the sharpest knife in the drawer when it comes to seeing the unexpected popping up in the garden. I had seen an upright plant with greenish-yellow flowers in a raceme in one of the species peony beds, and dismissed it (without a close look) as just another seedling of Digitalis lutea, the Small Yellow foxglove (a nice enough plant, but I've got lots of it). Then, this weekend a nursery customer saw it and commented on the wild native orchid amongst the peonies. Good grief, it was indeed!
Further discussion about how the peony beds were mulched with hardwood bark, and how numbers of the native orchids appreciate that kind of a growing medium. Always nice when the hitch-hiking seeds in a load of organic material are desireable rather than weeds! This is also a benefit of not weeding until the weeds show their flowers (well, that's my excuse; it's actually more like: not weeding until banks stop making obscene profits).
Addendum: I went looking for an identity of it, and have settled on it probably being Epipactis helleborine (common name Helleborine). It is wild, but not native, in North America, having come from Eurasia, possibly brought along by early settlers for its herbal properties (possibly involved in a putative cure for gout). It is perhaps a relatively recent immigrant to Nova Scotia, having been first reported only in 1985, and is slowly spreading from the few sites where it has been observed to date.