I'm in California in an Oak tree forest and I grow gopher purge (euphorbia lathyris, will self sow in shade), Feverfew (will self sow also), Foxglove (won't ss in shade but will bloom), and lycnis coronaria (might ss with water). These all take little water well, especially the feverfew, it's naturalized in some spots with no water.
If you decide to do pots let me know and I'll send you some Bletilla orchid bulbils, I grow mine in part shade and they always bloom. Definately try geraniums in the shade, some have great variegated leaves and are alright on the dry side.
Dee
