Posted: 01/05/2012 at 16:10
Heucheras do well in semi-shade, and you can get some very deep purple ones. The darkest one that I have is Obsidian, which is practically black. A good mid purple is Emperors Cloak.
Actea simplex 'Brunette' is a terrific plant for shade, deep purple finely cut leaves, 5 foot tall when its white spikes are in flower. I got one two years ago, at Holcombe Hall in Norfolk, and it is terrific, but it likes moist soil and doesn't like much sun. It would go really well in the middle / back of a border. Here's some info on it: