Have a look in here;

http://www.thegardenersalmanac.co.uk/Data/Plants%20for%20purpose/Plants%20for%20purpose.htm

Scroll down to the bottom of this page Click on S and then on shade plants. About 200 ideas there.

I have lots of euphorbia robbiae going begging if you think its worth coming to Haverfordwest for it - its all coming out sometime this week. It was the only thing that would grow under a conifer. This has now gone so I plan to replant with something else. PM me if interested.

If you want to add a little brightness to the shady area then Elaeagnus pungens maculata does well in this situation along with varigated euonymous.

i took my euphorbia up and planted crocosmia and that came great this year in the shade!