Plants that do well in hot conditions are those that are typically tagged drought-tolerant or heat-hardy. These are plants that are good in desert gardens or in really dry conditions like the Deep South. USDA hardiness zones over 7 need good heat-hardy plants to survive the temperatures of a typical summer season.
Adam's needle (Yucca filamentosa) is from the agave family. It is an easy-to-grow, evergreen perennial that is drought-tolerant. Leaves are strap-like and 2 to 3 feet long. Spikes get 12 feet tall with many white flowers that are 2 inches long. Grow Adam's needle in full sun or light shade in average to dry soil. It is hardy in USDA hardiness zones of 5 to 10. Propagate via offshoots, cuttings, or by seed.
Orange cosmos, (Cosmos sulphureus) is from the aster/daisy family. It is an easy to grow and fast growing annual that is drought tolerant and attractive to butterflies. It will get between 1 and 7 feet tall depending on the conditions and the cultivar. Yellow or orange flowers are 2 to 3 inches wide. Leaves are green and feathery. Grow orange cosmos in well drained sandy soil in bright sunlight. It is hardy in the USDA hardiness zones of 5 to 10. Propagate via fall or spring seed.
Lion's ear (Leonotis nepetifolia) is from the mint family. It is a drought tolerant annual that attracts hummingbirds. It can get 8 feet in height with smooth leaves 2 to 5 inches long. Flowers are 2 to 4 inches wide and 1 inch long. The blooms are orange and furry. Grow lion's ear in full sun to partial shade with regular watering. Propagate via seed. It is hardy in USDA hardiness zones 8 to 11.
Moss rose (Portulaca grandiflora) is from the purslane family. It is a drought tolerant annual that is good for container gardening. It will get 6 inches tall and 12 inches wide. Stems are red and leaves are bright green. Leaves are 1 inch long and flowers are 1 inch wide. Colors of blooms are red, yellow, white, pink, or orange and look very rose like. Grow moss rose in full sun in well drained soils. It is hardy in USDA hardiness zones of 5 to 11. Propagate via seed.