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 bentonii Opuntia bentonii Opuntia bentonii was proposed by some botanists to be a synonym of "Opuntia stricta". However, "O. bentonii", which grows in Texas, is separate and distinct from "O. stricta." "O. bentonii" was clearly described by Griffiths in 1911. Along with "O. stricta","O. bentonii" was one of the pest pears of Australia in the early Twentieth Century. Like so many "Opuntia" species, "O. bentonii" has been mistaken for a coastal form of "O. lindheimeri" in Texas, but there are sustained differences. For instance, "O. bentonii" plants are often less than 60 cm in height and the fruit is more globular