The oval or cylindrical, flattened, whitish-green,smooth joints reach up to 3 inches in length and have 5 to 8 greyish brown tipped spines of 1 inch extending from multiple small, white areoles. Joints will drop off easily. In summer pale yellow flowers rarely come to bear fruit, and then produce dry, spiny fruit. This genus has the largest membership of sun loving species. Australia has even banned a few species because of their rapid growth.