Opuntia robusta Opuntia robusta Opuntia robusta, the wheel cactus, nopal tapon, or camuesa, is a species of cactus in the Cactaceae family. It is native and endemic to central and northern Mexico to within 100 miles of the Arizona and New Mexico borders where it grow from 5,000 to 10,000 feet on rocky slopes, open shrub lands, woodlands and mixed with other cactus and succulents. Plants are commonly around high, though they may grow to over high when supported. The flattened stem segments are fleshy, round and blue-grey in colour. These are up to in diameter and have sharp spines up to
Opuntia ficus-indica the wild origin of "O. ficus-indica" is likely to have been in Mexico due to the fact that its close genetic relatives are found in central Mexico. "Opuntia ficus-indica" is polyploid, hermaphrodite and autogamous. As "Opuntia" species grow in semi-arid environments, the main limiting factor in their environment is water. They have developed a number of adaptations to dry conditions, notably succulence. The perennial shrub "Opuntia ficus-indica" can grow up to 3-5m height, with thick, succulent and oblong to spatulate stems called cladodes. It has a water-repellent and sun-reflecting waxy epidermis. Cladodes that are 1–2 years old produce flowers, the