|The green, branching, long and slender stem has cylidrical joints reaching between 2 and 8 inches in length. Two or more spines of yellow extend up to an inch from small areoles. In summer the bell-shaped, large red exterior and yellow interior flowers are borne singly on the stem tips and then produce red fruit. This genus has the largest membership of sun loving species. Australia has even banned a few because of their rapid growth.