Looks like a tree to me. I'm not good on identifying trees but it could be a willow of some variety, or perhaps a hornbeam. I've seen it lots of times.

Someone here will know for sure.

going by the catkin it is a willow of some kind. possibly the wild 'goat willow' also called 'pussy willow' which will grow into a substantial tree.
So unless you want a large tree then i'd just bin it. I pull out loads of seedlings/saplings every year.

welcome to GoY too :o)

Thanks very much for your replies, I really appreciate that, very useful. We only have a small garden now so theres not enough room for a substantial tree. Therefore, sadly I will probably have to get rid of this one! Thanks again for your help, and warm welcome to GoY xx

If a willow consider planting it along the edge of a stream (this is called a riparian area) instead of throwing it away. The willow roots will guard against stream bank erosion. You can do this public service in areas where permitted of course.

What a lovely idea, thank you Loosestrife2. It does seem such a shame to just throw it away. I will look into doing this. I am lucky enough to live in the Oxfordshire countryside so I am sure there will be an appropriate spot nearby x

Thank you Becmoore. In an area adjacent to Oxford University I was able to bring myself down to a lovely walking path(Lazenbee's Ground Walk) along the River Cherwell and do a virtual walk along it's banks and I see many areas where you could plant your little tree. Wouldn't it be nice to walk along that path to visit it now and then?

As US and UK laws are rather different I'd check with the council before you attempt to plant by the river Becmoore.

Never mind, its a nice pot. You can use it to grow something pretty!:)

Thanks all, yes I will definately check whether I am allowed to plant it first moon_grower, I dont want to get into trouble! I like the idea of planting it nearby so we can check on it from time to time, maybe when walking the dogs!

If I cant plant it by the river I could plant it at my nans, as she has a massive country garden and already has a few big trees. Much nicer than just binning it. As cottagekaren says I will now have to buy something else to put in the pot so a great excuse for a trip to the garden centre next weekend (one of my favourite places). I have an empty garden to fill so dont know where to start! Thanks so much for all of your comments x x

Sounds as if the pot didn't have drainage holes in the bottom hence the stagnant water.

I doubt you'll be allowed to plant it by the river. That sort of planting is strictly controlled.

Don't throw it away. Someone will want it, so advertise it on your local Freecycle website if your nan can't take it.

Well, I said in my initial suggestion " You can do this public service in areas where permitted of course". My suggestion of planting that poor little waif of a tree by that river was with that previous statement in mind. Funny, how one struggles to keep life on the straight and narrow when one day all that effort can be smashed to pieces by the tree police. Though worse than that can happen ...a friend of mine was doing just that, planting a few ornamental pear trees at his own expense in a public city park (had permission of course) when someone came up to him to rob him and my poor friend was shot in the robbery... he survived his wounds.