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 (less inclinded to narrow at the base). "O. bentonii" plants have fewer spines than "O. lindheimeri", zero to 3 (often only 1 or 2). One important difference is that the stigmas of "O. bentonii" flowers are yellow and not green as in "O. lindheimeri." Another individual feature of "O. bentonii" is that the veins are often visible between areoles. 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