Opuntia ficus-indica system. The plant may be used as an ingredient in adobe to bind and waterproof roofs. "O. ficus-indica" (as well as other species in "Opuntia" and "Nopalea") is cultivated in nopalries to serve as a host plant for cochineal insects, which produce desirable red and purple dyes, a practice dating to the pre-Columbian era. Mucilage from prickly pear may work as a natural, non-toxic dispersant for oil spills. A commercial use for "O. ficus-indica" is for the large, sweet fruits, called tunas. Areas with significant tuna-growing cultivation include Mexico, the Mediterranean Basin, Middle East and northern Africa. The cactus grows
Opuntia dulcis common in trans-Pecos Texas, New Mexico, and Arizona. It has been observed in the mountains of southern Nevada.. Opuntia dulcis Opuntia dulcis has been described as a variety of, and is confused with, "O. phaeacantha". However, "O. dulcis" is a larger plant with ascending branches, to 2 ft (exceptionally 4 ft). While it is a larger plant, immature specimens of O. dulcis may overlap in size with O. phaeacantha. "Opuntia dulcis" resembles "O. engelmannii" in some ways but does not become as erect or large as that species. Also, the spines of "O. dulcis" are finer than those of "O.