| The obovate, bluish when young, sea green, powdery joints, reach up to 6 1/2 inches in length and have 1 stiff, thick spine of 1 inch extending from upper and marginal areoles while yellow glochids cover the surface. In summer the large yellow flowers are borne singly and then produce red fruit. This genus has the largest membership of sun loving species. Australia has even banned a few species because of their rapid growth. |