Adders tongue fern

The Adders tongue fern Ophioglossum vulgatum, is found mostly in southern England and is quite rare. 
Compared with our other native ferns it is tiny and easily overlooked, consisting of one solitary elliptical leaf with a spike ~ 40mm long  with 2 rows of spores growing from it, from which it takes it's name.
It is a good indicator of ancient meadows, and can be found between June and August.
I found this one today, when I was at Box Hill in Surrey looking for orchids... that sadly aren't flowering just yet :-(