Where Does Photosynthesis Take Place in a Cactus?

Grand Canyon National Park/CC-BY 2.0

While different cactuses may have specialized photosynthetic techniques, in general, photosynthesis occurs in a cactus' stem or trunk. The concept of photosynthesis in a cactus or succulent plant may seem strange considering that most of them do not have obvious leaves like many other plants, but their stems or trunks serve the same photosynthetic function as some other plants' leaves.