Cactaceae

Plants of the Cactus Family

Opuntia polyacantha. Prickly Pear Cactus.

If you find a thick, succulent plant with clusters of spines it is certainly a member of the Cactus family. The regular, bisexual flowers are showy with numerous sepals, petals and stamens. The ovary is positioned inferior and consists of 2 or more united carpels (syncarpous) forming a single chamber. It matures as a pulpy "berry" with numerous seeds and usually spines. The cacti originated in the New World. Worldwide, there are now about 125 genera and more than 2,000 species. Sixteen genera are found in North America. Some well-known members of this family include peyote (Lophophora Williamsii), saguaro (Carnegiea or Cereus), Christmas cactus (Zygocactus), and the barrel cactus (Ferocactus). The spines of some species were once used as phonograph needles.

Key Words: Succulent desert plants with spines. Flower parts numerous.

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Coryphantha missouriensis. Missouri foxtail cactus.	Coryphantha missouriensis. Missouri foxtail cactus. Photographed near Three Forks, Montana.
Opuntia polyacantha. Prickly Pear Cactus.	Opuntia polyacantha. Prickly Pear Cactus with a shield bug. Pony, Montana.
Cylindropuntia bigelovii (a.k.a Opuntia bigelovii). Teddy Bear Cholla. Sonora Desert Museum. Tuscon, Arizona.	Cylindropuntia bigelovii (a.k.a Opuntia bigelovii). Teddy Bear Cholla. Joshua Tree National Park, California.
Opuntia leptocaulis. Desert Christmas Cactus. Arizona.	Opuntia fulgida. Chain Fruit Cholla. Sonora Desert Museum. Tuscon, Arizona.
Echinocereus fendleri. Fendler's Hedgehog Cactus. Near Portal, Arizona.	Ferocactus cylindraceus. Barrel Cactus. Lake Mead National Recreation Area.
Ferocactus wislizeni. Fishhook Barrel Cactus. Arizona.	Ferocactus wislizeni. Fishhook Barrel Cactus. Arizona.
Mammillaria tetrancistra. Common Fishhook Cactus. Arizona.	Mammillaria tetrancistra. Common Fishhook Cactus. Arizona.
Sclerocactus whipplei. Whipple's Fishhook Cactus.	Sclerocactus whipplei. Whipple's Fishhook Cactus. Grand Staircase-Escalante National Monument. Utah.
Echinocereus triglochidiatus. Claret Cup Cactus.	Echinocereus triglochidiatus. Claret Cup Cactus. Grand Staircase-Escalante National Monument. Utah
Carnegiea gigantea. Saguaro Cactus. Arizona.	Carnegiea gigantea. Saguaro Cactus. Arizona.