James Fong, Horticulturist | Asia, Australasia
As you take a stroll into the Australasia collection this time of year, you may notice the giant tree ferns or the magnificent rimu, but dive deeper into the collection, and you will find the vibrant, glowing, cone-like structures sitting in the trees and shrubs like ornaments on a tree. These are the flowering structures of the genus Banksia. Native endemic only to Australia and a couple surrounding islands, Banksia are among the most charismatic plant species from the Australian region. The cone-shaped inflorescence of the Banksia consists of hundreds or even thousands of individual flowers. These flowers are pollinated by birds, insects, and even small mammals like sugar gliders and pygmy possums!
Upon successful pollination, the woody follicles develop. Each follicle generally contains 1-2 seeds. As many of the species in this genus are native to areas that experience somewhat frequent fires, the follicles of serotinous (fire-adapted) Banksia species will retain their fruiting structures until a fire event, releasing the wind-dispersed seeds from within. Be sure to wander over to the Banksia during your next visit and admire their magnificent blooms and knobby fruits!
Diagram of Banksia flower structure: