Heuchera work well for me in sun and shade as well as Hosta. Astilbe are good for shade and part sun. As far as how they'll do in dry soil I'm not sure. You could amend the soil where you plant them, add some good soil to whats already there and add mulch on top to help keep in the moisture. And Hosta's and Heuchera have alot of different varieties to choose from varying in sizes and colors. Hope this helps.
Becca

I have sweet Williams around two Black Walnut tress that are in partial shade and full sun. Spiderwort might be another plant to consider. seagle52