Opuntia robusta aka Wheel Cactus

Opuntia robusta, also known as the wheel cactus, nopal tapon, or camuesa, is a species of cactus in the family Cactaceae. It is native to central and northern Mexico, growing up to 2m tall in its natural habitat. This shrubby or tree-like cactus has thick, flat, rounded, greyish or bluish segments that can reach up to 40cm across. Each areole on the stems produces 2-12 spines. In its native environment, Opuntia robusta can be found on rocky slopes, open shrub lands, woodlands, and mixed with other cactus and succulents at elevations ranging from 5,000 to 10,000 feet (1,500 to 3,000 m). Although mature plants produce shallowly bowl-shaped, yellow flowers up to 7cm across in summer, and spherical, red fruits, it is unlikely for these to be produced outside of its native range, such as in the UK. On the other hand, Bartolona is an extremely rare houseplant that requires very little water to thrive. It thrives best in long-lasting, direct light and should be positioned less than 1 foot from a window. This plant prefers soil that is extremely well-draining, and it is recommended to repot it each time it doubles in size. Fertilizers may not be necessary if this repotting routine is followed. In summary, Opuntia robusta is a native cactus species from Mexico, while Bartolona is a rare houseplant that requires specific care regarding water, light, and soil conditions.