Back to Factsheets | Download PDF |

Silver Banksia
Banksia Marginata
Family: Proteaceae

Botanical name:
In 1782, the father of modern plant classification, Carl Linnaeus, named the Banksia genus after Sir Joseph Banks, the naturalist aboard Captain Cook's Endeavour. Banksia marginata was first described by Antonio Jose Cavanilles in 1800. It is considered to be the most widespread banksia in eastern Australia. Marginata refers to the margins of the underside of the leaves which are slightly curved.

Common name:
The common name of silver banksia comes from the underside of the leaves which are white- some might say silver! However, the underside of the leaves certainly contrast with the top side of the leaves, which are a dull green.

The plant is extremely variable depending on environmental conditions. Most of the silver banksias in the Upper Barwon Region tend to be shrubs ranging from 1m tall (growing on poor heathy soils) to 5-6m in moist peaty sands. The tree form of the species is now very rare due to the severe depletion of its habitat on the basalt plains. Some of these remnants can get close to15m tall with 30-40cm diameter trunks. The leaves are variable as well- ranging from 4cm long to 12cm long. The bark is rough up to the small branches. The golden yellow flowers usually open in the autumn about the same time that seeds from the previous years' flowers are mature. The tree form can set very little seed due to lack of genetic diversity (inbreeding can cause infertile flowers and great distances between trees lessens the chance of cross pollination). The shrub form, which grows in healthy populations, doesn't set a lot of seed either but they do have a suckering habit which helps the species survive the poor soils and frequent fires of the heath. The production of seed does occur especially during years of good rain, but can be frustratingly hard to find!

Where do they grow:
In the Upper Barwon Region, the healthiest populations exist in woodlands or heathy woodlands on poor tertiary sands especially Bambra, Barwon Downs and Forrest. As soon as clay dominates (and becomes poorly drained), the silver banksia disappears. It grows in association with messmate, peppermint, austral grass tree, prickly t tree, native peas, common heath etc etc. The tree form grows mostly on well drained stony barriers in basalt soils in association with sweet bursaria, tree violet, blackwood, lightwood, drooping she oak and hedge wattle.

There has been a lot of work from DPI over the years to help the tree form produce seed by collecting pollen from various remnants and pollinating other remnants. A shortage of viable seed is a major hurdle. The shrub form is genetically diverse so as long as enough seed can be collected, revegetation projects which include local provenance silver banksia are important, but limited, due to where they can and should be planted (heaths etc). A lot of mature seed that remains in the cones will need to be heat treated to remove. The heat from a warm oven or barbeque will open the banksia cones revealing the winged seeds. Once the cones have opened, seed can be shaken out and sown in the autumn-early winter.

European Uses:
The wood of most banksias is limited in its use by the size and length of logs. However, the wood grain displays beautiful medullar rays which are striking to look at when used for decorating furniture or in wood turning. Banksias produce large showy flowers very suitable for the cut flower market. Silver banksia certainly has beautiful flowers but nowhere near as showy as many of the 70 odd other species of Banksia. Many of the prettiest of the Banksias are indigenous to Western Australia, and quite a number of these struggle to survive the wet winter climate in SE Australia.

Indigenous Uses:
All banksias produce copious amounts of nectar. Sweet drinks are made from steeping the flowers in water.

Native Trees and Shrubs, Costerman, Weldon 1981. 2.) Wildflowers of Vic, Corrick and Fuhrer, Bloomings 2002.
Australian Plant Genera, Baines,SGAP, 1981. 4.) Bush Medicine, Low, A&R, 1990.
5.) Bush Tucker, Low, A&R, 1989