Luckily an eagle-eyed reader was on hand to alert me to my mistake. So I've been back for a closer look.
The first thing I'd have noticed, if I'd bothered to get down and have a proper look at it in the first place, is its brown velvety stem (or "stipe"), fading to a pale apricot colour at the top ("the apex"). The stipe seems pretty tough and fibrous.
|From the Collins Complete Guide to British Mushrooms and Toadstools (a photographic guide)|
So, time will tell whether this guy passes the final test...
I couldn't find any spores.
UPDATE 16/02/16 - happened to be passing these mushrooms again yesterday and they were looking pretty fresh, so thought I'd take another sample and try and settle this once and for all.
Look! WHITE SPORES!
So we'll call this one Flammulina velutipes and be done with it.
For the record
Location: Woods Mill nature reserve
Grid reference: TQ217136
Entered into FRDBI: 13/02/2017