Many species of cacti from South America are commonly grown here in Tucson gardens. Not only are these South American cacti very easy to grow and require little water, but many of them also have extremely showy flowers.
I don't know the species of the cacti shown below as they came without name tags, but they are all available in Tucson plant and cactus nurseries. The flowers on this cactus are a dazzling, saturated red-pink.
Many cultivated cacti are night-blooming, like these little cacti shown below with their oversize, pale pink flowers. These cacti are especially nice in moonlight gardens or in evening, outdoor entertainment areas.
Another night-blooming cactus is this large, white-flowered Cereus shown below. The flowers open at night and persist for a little while after the sun touches them.