I hope to post some information here on native (eastern US) plants (mainly herbaceous) for drought conditions. I'm assembling the information from several sources: native plant nurseries, other on-line guides, books. One thing I've noticed is that different authorities do not fully agree on the cultural requirements of native species: wet vs. dry, heavy (clay) vs. light (sandy) soil, sun vs. shade. Why the disagreement?

(a) Controlled experiments, growing each species under a variety of conditions (soil type, light level, and moisture), would provide the most accurate answers to these questions. I doubt that such experiments have been done.

(b) Genetic variation within the species may lead to a variation in growth requirements. (Some individuals in a given species may be more drought tolerant than other individuals in the same species.)

(c) Most plants become more drought tolerant as their root systems develop. This is especially true of plants that produce deep tap roots (up to 20 feet deep for some herbaceous species). The genus Baptisia (False Indigo) is a good example.

(d) Related to (c), drought tolerance may depend on whether the plant is in its preferred soil type. For example, a species that prospers in sandy loam might wilt in clay soil because the roots can't grow in clay.

Sorry to confuse things, but I think it's important to point out that drought tolerance isn't as "cut and dried" as a simple list might suggest. The best advice is probably to take an experimental approach, and try a number of different plants to see what works best in your garden.

Every year at the county fair, the Montgomery County agricultual extension has a very nice display of nothing but native plants. I've also found the Univ of MD extension's site to be super helpful (can't remember its URL though :/)

If you're ever in the area (near New Hope, PA just over the Delaware River from NJ), Bowman's Hill is a beautiful place, and they propigate and sell native plants.

Here is a link that might be useful: Bowman's Hill Wildflower Preserve

aloe vera or medicine plant , prickly pear cactus (fruit strain ) there is also a Galopagos strain that is taller.
jojoba prized for its oil, will grow in desert conditions.
other possibilities that might work but might not: beach plums (the plums are the size of a nickel and have stones they are a low shrub) , bilboa tree from Africa , eucaliptus from Austrailia, monkey puzzel tree Patagonia ,
peach , almond . the most drought resistant corn is an american Indian strain sold by www.nativeseedsearch.org but i don't remember the strain. read up on deserts around the world and keep us posted on what you find . The most arid desert is in South America Argentina I think . check "xeriscape"or "xeroscape"