Would love to annie but I'm afraid I've no idea. Did you try a garden web orchid site? Or maybe the Name That Plant site, folks in there are pretty good.

Regards
B.

well, the thing is I'm a lazy sod and I tried one of those sites and it was asking me what size was "this" and what colour was "that". I didn't have a clue what it was talking about and I figured I'd have to actually learn (gasp!) what the bits and pieces were called before I could answer anything. So I thought I'd check here first...sigh. Have to work it out, don't I?...sigh.

Hi Annie
A bit fuzzy but I think most likely its Dendrobium linguiforme, which is a creeping orchid common name "tongue orchid".
Unless the leaves are really really lumpy and bumpy in which case it could be dendrobium cucumerinum, "Cucumber orchid". Google some images and see what you think.
cheers

thanks Alison. Definitely the Dendrobium linguiforme. I got a little piece of it years ago from a friend of my sisters. Stuck it on a tree and forgot about it. Then one day, I was looking at something else and, lo and behold, there were these microscopic (just about!) little orchids there. It hardly ever seems to flower but then, where it is, isn't easy to see. Maybe I should move it somewhere where I can keep an eye on it but it's growing and I hate disturbing anything that actually seems to be happy! btw, just about lost one of my Worsleyas beginning of this year but it looks like it may have survived. Fingers Crossed. :):):)

A while back this orchid was renamed Dockrillia linguiforme but looks like it's been changed back to Dendrobium again.