Artists - I need advice on a painting

Some years ago I was wandering round a car boot sale in Essex and saw what I thought was a print of a lake. Closer examination showed it was a painting not a print. I bought it for just £8.00.

Now I'm no artist and I have no idea what medium this painting used. I don't think it's a watercolour but it has a dull surface, not shiny like a varnished oil painting.

Here's a close-up of the signature:

I can't make out the artist's name either. You might be able to see a little of the texture of the paint though. Those fine branches are raised out of the surface and easily felt.

The painting is done on canvas and is full of colour but as I said, the surface is dull. Does it need varnishing?