|Thick, erect, brushlike, with 8 or 9 grey spines reaching up to 2 inches long. The flat, grey-green joints, are oval, 2 inches long with many small warts. Small hairy areoles have reddish tufted glochids. In summer the bell-shaped, large flowers are borne singly on the areoles of new joints and grow about 2 inches long and then produce spiny, warty fruits. This genus has the largest membership of sun loving species. Australia has even banned a few because of their rapid growth.