 Banksia prionotes , commonly known as acorn banksia or orange banksia , is a species of shrub or tree of the genus Banksia in the family Proteaceae . It is native to the southwest of Western Australia and can reach up to 10 m ( 33 ft ) in height . It can be much smaller in more exposed areas or in the north of its range . This species has serrated , dull green leaves and large , bright flower spikes , initially white before opening to a bright orange . Its common name arises from the partly opened inflorescence , which is shaped like an acorn . The tree is a popular garden plant and also of importance to the cut flower industry . 
