Tree Pear & Prickly pear

When I left Goondawindi I could not help but notice what I thought were giant prickly pears but apparently they are not. They are tree pears. I am told that both are declared pests but the prickly pear has mostly been eradicated whereas the tree pear has not. Farmers are not so concerned about tree pear as they have few spines enabling cattle to eat them during a drought and it does not spread as fast as prickly pear. The tree pear has an deep orange flower and red fruit while the very prickly prickly pear has bright yellow flowers and dark purple fruit.