Prickly pear cactus, photographed in an open space in Cave Creek AZ, in July 2021.
The edible parts include the fruit, leaves, flowers and stems.
Prickly pear cactus can be eaten whole, boiled or grilled.
In Arizona sometimes we can see it for sale is in the form of juice and jams.
I can see somebody started eating it raw here, on the stem ...