I am getting better at taking care of cactus plants. This is Tiger Jaw Cactus. It tried to die while it was growing beautifully two summers ago. I thought in summer, it's okay to water it, especially the sun heats the patio door close to 105'F at least during summer. But it showed the sign of rot. I quickly pinched off the top groups of new petals and replanted it. Fortunately that saved the plant. Now I have three pots of them growing happily. To my surprise, they even flowered. I think it is very rewarding when the cactus flowers. You never know if they will flower or when.
They bloom open in the morning and closes as the sun goes down.