I saw this *mystery* at Carlton Marshes in an area of long dry grass ten days ago. I assumed it would be a kind of cocoon, but with the magnification of the photograph, I am not so sure.
I can fairly safely discount 'mineral', but is this 'animal' (e.g. cocoon/s) or 'vegetable' (fungi or mould perhaps ...)? Something akin to ergot came to mind, but ergot doesn't seem to fit.
Do let me know if you can solve my mystery! Thank you.
STOP PRESS, 10 SEPTEMBER 2013 My sincere thanks to all who put in their pennyworth in the Comments below. I *believe* Wilma may have set me on the right track with her suggestion of water snail eggs or egg cases. It is not something that would have crossed my mind, but the stalk was just by a special water course inhabited by rare Fen Raft Spiders (which sadly I didn't see), so it sounds plausible. Unfortunately the wind was blowing, as it often does over the marshes and fens in my region, and it was hard to get the camera to focus on a single swaying strand of grass! Take a look at these pages here and here and ... and although these ones found by Google are of Apple Snails in the USA rather than a snail species at Carlton Marsh, I think you will get the picture. Thank you all once again!
LATEST UPDATE, 11 SEPTEMBER 2013 It seems it may be 'vegetable' rather than 'animal' after all! Phil of the Cabinet of Curiosities blog has offered the following: 'Hi Caroline, There's a photograph of something similar at http://homepage.eircom.net/~hedgerow16/oct21.htm. There's a discomycete fungus called Lachnum virgineum that looks rather similar when it has dried out a bit, which sometimes grows on dead plant stems...' Thank you, very much, Phil, for this.
LATEST UPDATE, 9 APRIL 2014
Neil Mahler, County Fungus Recorder, Suffolk.