|This deep coppery-green, upright, branching, bush reaches
between 9 and 20 feet in height, has barbed spines in the wild
but is spineless in cultivation. The joints are elongated-oval
or oval and grow to 10 inches in length, 1 to 2 inches wide. The
short yellowish glochids extend from yellowish areoles. In
summer the bell-shaped, large yellow flowers are borne singly on
the stem tips and then produce reddish, subglobose fruit. This
genus has the largest membership of sun loving species.
Australia has even banned a few because of their rapid growth.