The Suffolk Serapias: Further Update

 This post deals with the identity of the Serapias orchid I found in June in Suffolk. When I found it I initially proposed it was the long-lipped tongue orchid (Serapias vomeracea), however recently I began to have doubts. For a start, a quick recap of the photos to show any possible identifying features:

Now, as I have said before, the pattern on the 'tongue' of the orchid immediately rules out Serapias lingua- a factor confirmed by the Field Guide to the Orchids of Europe and the Mediterranean. Serapias parviflora is also ruled out based on the size and shape of the flowers. This no doubt disappointed many because this leaves just one small-flowered tongue orchid colony in the UK, and that rooftop garden has been declared off limits to visitors. 

The two likeliest orchids that I have found are Serapias vomeracea, and Serapias bergonii. Serapias vomeracea seemed likeliest to me initially, however, these plants are extremely hairy along their proximal third (thought not always). The best way to tell them apart, however, is the relative width of the hypochile and epichile: the bergonii orchid, also known as the lax-flowered tongue orchid and sometimes considered a subspecies of S. vomeracea, is usually much narrower in the hypochile and epichile. Unfortunately, I didn't have a ruler with me when I was out with the orchid, but one of my photos does show the 'tongue' in comparison with my finger (first photo). That part of my finger is slightly broader than 1cm. Compare that with the width of the epichile: at its widest, it still appears at the most half of the width of my finger. This would, as an incredibly crude approximation, put the width of the epichile (or tongue), at around 7mm. The nominal S.vomeracea, however, has an epichile significantly wider than this, at 9 to 13mm. Serapias bergonii, however, has an epichile which is 4-8mm wide.

As a result, the approximate measurements fit Serapias bergonii but do not fit Serapias vomeracea, which, in my eyes, confirms that my initial identification was incorrect, and that the mysterious Suffolk orchid is indeed Serpias bergonii, the lax-flowered tongue orchid. Now with the orchid's UK population down to a single plant (the other plant, I'm told, was stomped and stood on by careless orchidophiles), it remains the 2nd rarest orchid species in the UK