More unusual perennials for a hot sunny garden.

Passiflora caerulea
Not strictly a perennial, but effectively that in my zone 7a garden.

zauschneria arizonica, almost a weed here MD
A vigorous grower in mineral soil and full sun. It is a modest bloomer in the summer.

I have been puzzled by the plant's reluctance to bloom heavily. Any guesses by denizens of the southwest would be welcome

Berlandiera lyrata : dry plains of New Mexico
Called chocolate flower. On hot sunny mornings it smells like intense, expensive belgian chocolate.

This little known desert composite is easy in full sun and mineral soil. It blooms from May to September. At evening the flowers nod like praying nuns.