I don't find bee balm very drought tolerant. Some of the other Monarda species are, though, such as horsemint and wild bergamot M. fistulosa.

I would also add yuccas, many of the hardy Euphorbia species, echinacea and some rudbeckias, echinops, lavender, of course any hardy cacti or succulent, Zauschneria, and many ornamental grasses.

In my own garden I notice the water conserving plants are Helianthus 'Lemon Queen', Heliopsis 'Tuscan Sun', Veronica 'Speedwell Royal Candles', Nepeta's 'Walkers Low' and of course Eryngium 'Big Blue'.

Rouge21, I forgot to mention Helianthus, Lemon Queen. That's a great plant and is definitely drought tolerant in my yard as are the ornamental grasses.

Lavender, Platycodon (balloon flower), Asclepias (butterfly weed) and Penstemon.

I'll add to the above lists that all of my
sedums,creeping thyme, and big root geraniums have been tolerant of the present hot,dry conditions.

As odd as it may sound Astilbe pumila does really well during drought years.

Kevin

Oregano- very hardy, spreads into a large clump, stays green in winter, and has beautiful heads of bloom this time of year. Also, "Crazy Daisies" -given to me by a friend, so I don't know the actual name, but they get over 5 ft tall and flower the end of summer/fall and they spread. Yarrow (Achillea)- not the floppy type but the tall, sturdy ones, ("Gold Plate", I think)- love them. Gaillardia, too. Here, they not only have to deal w/ heat & humidity but they're also planted in sand.

verbascum,
salvia greggii and other shrubby new world salvias
limonium
osteospermum jucundum
nepeta (Various)
centaurea
althea cannabina
verbena bonariensis
indigofera
eryngium
toadflax
linum
sedum
scabious columbaria and ochraleuca
jasione
gaura
erodium chrysantha
euphorbia myrsinites
lavenders
perovskia
santolina
arctotis
erm, I know some of these are technically shrubs or sub-shrubs but they all grow in my no-watering gravel garden.

Well this is my first year at gardening, but I am really enjoying the Arizona Sun Gallardia.....the color is just awesome on these things.

Most of the ones already mentioned. We got hit with a bad heatwave for almost a month last year. Gaura was the only plant blooming its little head off.

Since most of the ones I'd suggest have been mentioned I will throw in Asters, at least for me. Once they get going in their second year I barely have to do anything to them, watering included. Pinch them back twice early and then just let them do their thing.

1.) Cactus
2.) Yucca 'Color Guard'
3,) Delosperma cooperi
4.) Delosperma dyeri
5.) Delosperma 'Lavender Ice'
6.) Hesperaloe parviflora 'Brakelights'
7.) Hesperaloe parviflora 'Yellow'
8.) Kniphofia

I'd also like to add helianthus, Lemon Queen and a rudbeckia nitida, Autumn Sun.