Opuntia in the food web. Charles Darwin was the first to note that these cacti have thigmotactic anthers: when the anthers are touched, they curl over, depositing their pollen. This movement can be seen by gently poking the anthers of an open "Opuntia" flower. The same trait has evolved convergently in other cacti (e.g. "Lophophora"). The first introduction of prickly pears into Australia is ascribed to Governor Philip and the earliest colonists in 1788. Brought from Brazil to Sydney, prickly pear grew in Sydney, New South Wales, where they were rediscovered in a farmer's garden in 1839. They appear to have
Opuntia basilaris These are more or less blue-gray, depending on variety, long and less than wide and thick. They are typically spineless, but have instead many small barbed bristles, called glochids, that easily penetrate the skin. "Opuntia basilaris" blooms from spring to early summer. The species is variable in nature and several names under different ranks have been described. Only four of these are generally accepted. Some experts consider the Trelease's beavertail to be a full species (Bowen 1987, R. van de Hoek). It is unique among the varieties of "Opuntia basilaris" in that the areoles contain spines in addition to the