There are not 29 orchid species still to flower at this time of year, the Green-winged (not green-wing) Orchid and the White Helleborine are NOT rare (probably the commonest orchids in Britain after the Common Twayblade)…
The article about the Frog x Common-spotted Orchid in Cumbria was much more exciting – do try to keep up!
The Green-winged and White Helleborine are more common than Common-spotted, Early Purple and Pyramid?
I know of one site alone where I can find Common Spotted, Early Purple, Pyramid, Frog, Fly, Lesser Butterfly, Twayblade and Marsh Helleborine, but I don’t know of anywhere that White Helleborine grows, or Green Winged, so I would suggest that they’re perhaps not as common as the Common-spotted, Early Purple and Pyramid.
At the right time of the year I only have to cross the road from where I work on an industrial estate in Chippenham to see Bee Orchids growing in serious numbers, with some Pyramid Orchids thrown in for good measure.