Strawberry Bank is a Gloucester Wildlife Trust reserve near Stroud. It was a warm sunny afternoon and the forecast was good so I went in my sandals and didn’t take a coat. The rain started just as I left the car, but I made my way down a footpath, through long wet grass and mud, got a bit lost, washed my feet in a stream, went along the lane, up through a patch of woodland and found the right spot. There was a group of butterfly spotters looking for Marsh fritillary, which was nowhere to be seen in the drizzle. At least orchids don’t fly off when it rains. They recommended a visit to nearby Selsey Common, so I went on there afterwards (pictures to follow in another post) and the rain got heavier.
The lesser butterfly orchids (Platanthera bifolia) are beautiful stately and elegant. White and green flowers which look individually like a miniature cartoon ghost. The easy way to tell them from the Greater butterfly orchid (Platanthera chlorantha) is by looking at the pollinia, the eyes of the ghost. In the ‘greater’ they are angled and in the ‘lesser’ they are parallel. The ‘lesser’ are supposed to be smaller and more dainty, but are not necessarily.
Dr Richard Bateman from Kew has spent years measuring recording and DNA sequencing the butterfly orchids. He states that there is not sufficient genetic difference to regard them as two distinct species. He said that there is more genetic variation between two unrelated humans than there is between these two orchid species.
But there are distinct populations of each and some hybridisation where they occur together. P bifolia has the heathland form, growing in acid soils, and woodland form often in calcareous beechwoods. P chlorantha can also be seen in grassland or woodland, but nearly always on calcareous soil.
Lesser butterfly is classified as a vulnerable species with 64% of historical sites lost and as ever that is due to changing farming practices, loss of heath, deciduous woodland and loss of wildflower meadows.
It rained all afternoon, I kept my camera dry under my t-shirt and I was soaked through by the time I got back to the car, perhaps it’s a necessary rite of initiation for a new orchid hunter.