Opuntia and related species (= opuntiads) are unique cacti with unusual shapes and beautiful flowers. There are over 90 species of Opuntia in the United States and many more in Mexico and the rest of the Americas. Opuntia Web describes opuntias of the United States. Cholla Web is our sister Website, and it describes other opuntiads of the USA (chollas and dog chollas).
Of the many opuntias in the United States, some have been forgotten by time, and other names have fallen by the wayside. Some opuntias look superficially alike and only close inspection can tell them apart (e.g., O. humifusa and O. mesacantha). Thus, casual observation might indicate one species where there are actually two. We use historical and current records along with field studies to identify them, their differences, and their similarities.
What We Do
We describe the various species, and we provide multiple photographs so you can see details. We try to take photos in habitat so that you can see how the plants grow and what they look like in different seasons. The goal is to describe them in easy-to-understand terms. A group of editors verifies all the information in this Website, and we strive to present accurate information. But we are always happy to learn new things. If you find an Opuntia, maybe we can help you identify it. Just write to us or leave a comment.
We generally do not described Opuntia hybrids though there are many beautiful plants in gardens. Though hybrids occur in Nature, they are nearly impossible to identify properly and are not the norm. We concentrate on species.
Opuntias are unique and worth studying because:
- they are so numerous in the warmer parts of the county and prominent plants in some gardens,
- it is a fun detective story to find the original publications and match them with the plants,
- they have unique drought resistant properties, and
- they have beautiful flowers and edible fruit.
Through they are mostly desert species, there are species that will grow in the southeast, the northeast, and the upper Midwest. Many opuntias grow in climates without strong freezes, but some come from northern areas or high altitudes and fly through winters of exceptional cold. We like to grow Opuntia, and writing about them helps us and others understand the species and decide what to grow.