Beautiful exemplar of cactaceae commonly known also as ‘wheel cactus’ in reference to the circular shape of its stems. It has a shrubby appearance consisting of a glaucous green stem, very branched, which can reach even a height of 6 m. The ramifications are very often considered as leaves thanks to the flattened and fleshy appearance; above which we find some white woolly areolas. Acctually, the very small leaves of O. robusta bloom at the base of the areoles; they are reddish, scaly and with the growth of the plant tend to fall. Its spines are rarely present; they have brown or yellowish hues and are robust. The beautiful flowers of this cactus are small, they grow at the apex of the segments or ramifications; with bright yellow petals, reddish tips and green hues in the center.