Only one plant seen in a couple of hours of swamp slogging. The very flat labellum callus makes it this species (by contrast with the channelled labellum callus of P. canaliculatum, also in this general area). P. wilkinsoniorum has been found in bogs to the north and south of this one. This bog was burnt in early 2020.
Not positive of this ID. On Copeland and Backhouse's photos it could also be archeri or formosum, both potentially also flowering in Dec. In a montane bog at 910m elevation. Just one plant seen, about 15cm high, with about 12 small flowers.