 The structure of the Banksia flower , with the style end functioning as a pollen presenter , suggests that autogamous self @-@ fertilisation must be common . In many Banksia species , the risk of this occurring is reduced by protandry : a delay in a flower 's receptivity to pollen until after its own pollen has lost its viability . There is dispute , however , over whether this occurs in B. prionotes : one study claimed to have confirmed " protandrous development " , yet recorded high levels of stigmatic receptivity immediately after anthesis , and long pollen viability , observations that are not consistent with protandry . 
