Saguaro cactus will produce flowers during late spring into early summer. In average years, the flowering occurs between April and June. The flowers are a milky white, and emit a sweet nectar which attracts multiple species of bats. These bats feast on the flower nectar, and in process act as pollinators for the saguaro cactus. As the cactus produce fruit, the bats will start to eat the fruits, and in turn help spread the saguaro seeds across the desert. Source NPS –

The flower opens around dusk when temperatures are lower they close midmorning as temps begin to rise. A single saguaro can produce 1000 flowers. https://www.youtube.com/watch?v=IIH22km-Y_4

Lastly the cactus is the state flower of Arizona, I know it doesn’t look like a flower but there you have it. Hope you’ve enjoy a quick glimpse into the Saguaro World!

Link(s) of interest

https://www.britannica.com/video/22443/Plant-life-Sonoran-Desert-Saguaro-National-Park