For some spring flowers I would recommend Anemone patens, Geum triflorum and Tradescantia spp., Lithospermum canescens, Trillium recurvatum

Summer: Allium cernuum, Coreopsis palmata, Dalea purpurea, Penstemon digitalis, Phlox pilosa, Pycnanthemum virginianum, Rosa carolina, Ruellia humilis, Silene regia, Thalictrum dasycarpum, Veronicastrum virginicum, Helianthus mollis, Asclepias purpurascens

For fall color Aster azureus, Solidago ptarmicoides, Solidago speciosa, Verbena stricta

Thanks Lycopus! Those are some really great suggestions, and I will almost certainly be using some of those now.

tickseed, ursinia, gaillardia, zauschneria
indogofera, baptisia. lespedeza, cytisus, salvia neurepia, salvia greggii, arctotis, toadflax, flax (annuals and perennial) verbena, althea cannabina, limonium, platystemon, gladiolus byzantinus, alliums (some) nepeta, scabious, knautia macedonica, helianthemum, cistus, gysophila

You should know, of course, to match your plantings with local genotypes. Plants that are typically grown in your region. Ive had great success with making sure my plantings are not from a region very far away (200 mi square) from my back yard. Avoid suggestions of plants from UK (!!) or Washington state or S. Mississippi! LOL! Hope Im not too late posting...

I am also doing a Mesic/Dry prairie garden going on three years at it. You listed E. paradoxa. Do you mean Fallugia paradoxa? I have that one I grew from seed years ago and its one of my favorites. Another favorite shrub is Chamisa.

Actually, I took out the entire lawn, front and back, and the whole thing is a dry prairie. I have many varieties of winter hardy cactus, winter hardy agave, SW Natives and grasses, Desert Spoon, Beargrass, and many Desert and arid type perennials.

I started adding the grasses last fall. My favorites are Little Bluestem, Blue Gramma and Stipa tennussima. I got 4 of the huge Giant Sacaton grasses from High Country Gardens and they are supposed to be monsters.

Two plants that add lots of color that have naturalized and which bloom non stop all spring/summer/fall are Desert Marigold (Baileya multiradiata) and Flame Flower. I absolutely recommend the desert marigold! I put in some varieties of penstemon last year and they bloomed gorgeous this spring. Very impressive was Penstemon palmeri (Pink Wild Snapdragon).

I ordered a Prince's Plume (Stanleya pinnata) from Great Basin natives and also a Mormon Tea and both are in their third year going strong. I have many other perennials from when I ordered seed from Plants of the Southwest and I traded a lot with a woman in Texas who sent me Texas natives. I can make list of other suggestions if you are interested. I also ordered some mixed wildflower seed from the Sonoran Desert and got some that way. Its an addictive thing, collecting plants that have a "certain look". It its rangy and odd or rugged, I love it. Its fun to figure out what some unknown something is by searching on line too.