![Mammillaria tetrancistra showing fishhook spines](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2017/05/mamm-tetrancistra-johnida-dockens.jpg?resize=896%2C980&ssl=1)
Author: Joseph
![Mammillaria tetrancistra showing fishhook spines](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2017/05/mamm-tetrancistra-johnida-dockens.jpg?resize=896%2C980&ssl=1)
![Stenocereus thurberi, Geir K Edland](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2017/05/stenocereus-thurberi-Geir-K-Edland.jpg?resize=980%2C800&ssl=1)
Stenocereus thurberi, Organ Pipe Cactus
![Cereus hildmannianus, el Cajon Yacht Club](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2015/11/Cereus-hildmannianus-el-cajon-yacht-club.jpg?resize=980%2C803&ssl=1)
Queen of the Night
![Puya venusta X chilensis, Patricio Novoa Quezada](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2017/05/Puya-venusta-X-chilensis-pnq.jpg?resize=980%2C799&ssl=1)
Puya
![Cleistocactus smaragdiflorus flower, Peter A Mansfeld](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2014/12/cleistocactus-smaragdiflorus-Peter-A-Mansfeldb.jpg?resize=893%2C507&ssl=1)
Cleistocactus
![](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2014/12/hilaria-rigida-cal-photos3.jpg?resize=683%2C512&ssl=1)
Nurse Plant Hilaria rigida and Agave deserti
![Aloe capitata cipolinicola](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2014/11/a-capitata-cipolinicola-cd5.jpg?resize=980%2C768&ssl=1)
Aloes from Madagascar
![Opuntia macrocentra, Matt Baker](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2015/10/opuntia-macrocentra-matt-baker.jpg?resize=980%2C800&ssl=1)
Floral Biology of Opuntia macrocentra
![Black-tailed jackrabbit](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2014/12/jackrabbit-ed-schipul.jpg?resize=854%2C569&ssl=1)
Opuntia Interactions with Rabbits, Hares, and Rodents
![Gymnocalycium saglionis](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2014/11/MG_4448.CR2-gymnocalycium-saglionis.jpg?resize=980%2C740&ssl=1)
Gymnocalycium in Argentina
![Echinocactus polycephalus xeranthemoides](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2014/12/echinocactus-polycephalus-xeranthermoides-nh.jpg?resize=980%2C980&ssl=1)
Echinocactus polycephalus
![Opuntia pyrocarpa](https://i0.wp.com/opuntiads.com/oblog/wp-content/uploads/2014/11/opuntia-pyrocarpa-DSC00036.jpg?resize=980%2C833&ssl=1)