What are good flowering plants that tolerate high heat and lots of sun?

Question

I am attempting to set up a rectangular planter in the foyer at my workplace. It is all windows with a mostly southern exposure in Colorado. It receives several hours of afternoon sunlight, gets very hot (80-90 degrees), and (to keep things honest) may or may not get regular care. I would like something that is “pretty” all year round, whether flowering or not. Thanks in advance for your wisdom and guidance.

Answer 1

These articles may help with suggestions: https://www.gardeningknowhow.com/ornamental/flowers/fgen/full-sun-plants.htm
https://www.gardeningknowhow.com/special/xeriscape/drought-tolerant-flowers.htm