 Banksia prionotes × hookeriana has also been verified as occurring in the wild , but only in disturbed locations . The two parent species have overlapping ranges and are pollinated by the same honeyeater species ; and though preferring different soils , they often occur near enough to each other for pollinators to move between them . It therefore appears that the only barrier to hybridisation in undisturbed areas is the different flowering seasons : B. prionotes has usually finished flowering by the end of May , whereas flowering of B. hookeriana usually does not begin until June . In disturbed areas , however , the increased runoff and reduced competition mean extra nutrients are available , and this results in larger plants with more flowers and a longer flowering season . Thus the flowering seasons overlap , and the sole barrier to interbreeding is removed . The resultant F1 hybrids are fully fertile , with seed production rates similar to that of the parent species . There is no barrier to backcrossing of hybrids with parent species , and in some populations this has resulted in hybrid swarms . This raises the possibility of the parent species gradually losing their genetic integrity , especially if the intermediate characteristics of the hybrid offer it a competitive advantage over the parent species , such as a wider habitat tolerance . Moreover , speciation might occur if the hybrid 's intermediate characteristics allow it to occupy a habitat unsuited to both parents , such as an intermediate soil type . 
