Some ferns (Holly Fern and Autumn Fern)do well in dry shade, and you could check out cast-iron plant too. Hosta are great once established and don't forget Lenten Rose.

Camellia bushes are great once estalished. I want to plant more in my garden. Cannas, autum joy sedum and forsythias all seem to do great in this drought.

lantana holds up well in dry conditions for sunny areas and blooms through fall.

I planted several plants this past May only to leave town for June & July, letting the plants fend for themselves without any watering. At the end of July there were left:

Pineapple Sage
Salvia Coccinea (a red-flowered sage)
Trachelospermum jasminoides
Decumaria (the native cl. hydrangea)
Geranium maculatum
Foam Flower
Thalictrum spp. (aka. Meadow Rue)
Celadine Poppy
Iris cristata (dwarf crested iris)
Bloodroot
Marginal Wood Fern
Christmas Fern (suffered terribly though)

I also seeded zinnias which did well, too.

Most of the above are natives and a probably adapted to surviving drought. They may not flower much during drought though. The sages don't seem to have bloomed since we left, but the last two or so weeks of storms have brought new buds out; the should bloom any day now.

There are several beautiful native shrubs, too, which once established survive drought. Calycanthus floridus (Sweetshrub) smells nice when you pass it. I had to protect ours from deer, though.

I second lantana. I bought a flat pak of 18 at Home Depot and they are still going strong with minimal watering. I'm hoping some survive the winter.

Established roses stand up well, as long as they are mulched. I've been watering mine about once a week, deeply. I may water more in anticipation of the late summer/fall flush.

I have Chelone "Hot Lips", three different types of toadlily, rodea, perennial begonias all blooming or heady into bloom in dry shade gardens. For texture there is fatsia japonica, cast iron plant, and other plants mentioned above.

GGG

Hydrangea paniculata's, Plumleaf Native Azaleas, Hostas, Oxblood lilies, Weeping Buddleja (Rostrincula dependens), several Tricyrtis cultivars, Clematis, Hardy Begonia and a tender one that spends summers outdoors, Tibouchina cvs.(intermittently), Lantana, A few Gardenia blooms now and then, same with Celandine Poppies and Corydalis lutea, Serissa, Drimia(Scilla), Nicotiana and those ubiquitous red-flowered Annuals that everyone has to have.
Variegated foliage perennials, shrubs and trees(JM) are a must in the summer garden for color contrast. Some of the one's I grow are Hydrangea 'Tricolor' & 'Quadricolor', Pieris japonica 'Variegata', Osmanthus heterophyllus 'Variegatus', Rohdea japonica 'Albomarginata',Ligularia (Farfugium) (Leopard Plant), Aucuba 'Gold Dust', Variegated Solomon's Seal and Japanese Fairy Bells, Acanthopanax sieboldii and dozens of variegated Hosta.
Everything seems to be holding up fairly well, considering the absence of normal rainfall. My major concern is the mature trees and the long-term damage they may suffer. Uninformed officials that order draconian watering restrictions have no clue as to the damage that is being inflicted upon the landscape.
Rb