Opuntia aurantiaca Opuntia aurantiaca Opuntia aurantiaca, commonly known as tiger-pear, jointed cactus or jointed prickly-pear, is a species of cactus from South America. The species occurs naturally in Argentina, Paraguay and Uruguay and is considered an invasive species in Africa and Australia. It was declared a Weed of National Significance by the Australian Weeds Committee in April 2012, and was reported by the Committee to be the most troublesome of all cactus species in New South Wales and the worst Opuntia species in Queensland. It is currently controlled biologically in Australia using the cochineal insect "Dactylopius austrinus", and to a lesser extent
Opuntia arenaria Opuntia arenaria Opuntia arenaria was considered a variety of "O. polyacantha" by many botanists, and is still treated that way in the Flora of North America. However, "O. arenaria" is diploid and "O. polyacantha" is tetraploid. It was described by Engelmann in 1856. "Opuntia arenaria" can grow in soil that is essentially pure sand. It has rhizomes up to 1.5 m long that give rise to above ground shoots with small cladodes that are 4-7 x 2–3 cm in size. Major spines are found in the distal areoles and are often reflexed, up to 30 mm long. Minor spines are