what to plant in damp soil, shaded area with height?

Try Cornus orange or red, it may serve the purpose.

And for flowers, Lysimachia clethroides and L. punctata. Cornus alba Elegantissima does well in shade - retains its variegation well, gets large, needs pruning. Mahonia aquifolium, which flowers, is evergreen, but slow growing and only reaches 3/4 feet.

Hostas and ferns love these conditions - there are some beauties available!