Opuntia argentina
Description:
A tree-like species which grows up to 50 ft tall in its natural habitat. It has a thick, cylindrical, fresh-green trunk 2.5 to 3.5 inches thick and cylindrical branches bearing flat oblong joints 2-4.75 long with one, rarely more, slender spine up to half an inch in length. It flowers by day mid-summer , the flowers are greenish-yellow with red fruits