Saguaro National Park is home to 25 species of cactus ranging from the towering saguaro cactus (Carnegiea gigantea) to the tiniest type of cactus in the park, the mammillaria (Mammillaria spp). The most common cacti species at Saguaro National Park and within Tucson, Arizona include:
- Saguaro cactus (Carnegiea gigantea)
- Fishhook barrel cactus (Ferocactus wislizenii)
- Staghorn cholla cactus (Opuntia versicolor)
- Pinkflower hedgehog cactus (Echinocereus fendleri var. fasciculatus)
- Engelman’s prickly pear cactus (Opuntia engelmannii)
- Teddybear cholla cactus (Opuntia bigelovii)
- Chainfruit (jumping) cholla cactus (Opuntia fulgida)