Hairpin banksia – wadanggari

What is a hairpin banksia?

The hairpin banksia is a shrub native to the east coast of Australia. Hairpin banksias are a relatively short plant ranging between one to 3 metres in height. The Darug Peoples refer to banksia as  wadanggari.

During autumn and winter hairpin banksias feature large cylindrical flower spikes ranging from 10 to 20 centimetres long. The flowers can be brown, red, orange or gold. The leaves of the hairpin banksia are long – 3 to 8 centimetres in length. They are narrow – 2 to 7 millimetres wide. The trunks have smooth, grey-brown bark.

There are three different varieties of hairpin banksias, each differing in height and leaf shape. The scientific name for the hairpin banksia is  Banksia spinulosa.  Banksia  commemorates Sir Joseph Banks, the botanist who travelled with James Cook on his first Pacific voyage.  Spinulosa, meaning small spines, refers to the bluntly pointed tips of leaves. Hairpin banksias are not so spiky and so are not painful to touch.

Hairpin banksia leaves and flower cone

Where are hairpin banksias found?

Hairpin banksias grow in sandy soils which are moist but drain easily. They are found in eucalypt forests  and woodlands between Australia's eastern coastline and the Great Dividing Range.

Hairpin banksias are common in Sydney bushland.

What eats hairpin banksias?

Like other banksias, the flowers of the hairpin banksia produce a large amount of nectar. The nectar attracts many native nectar-feeding bird species such as honeyeaters and spinebills and small mammals such as antechinuses and  ringtail possums. The flowers also attract a wide variety of invertebrates such as bees.

Eastern spinebills use their long beaks to probe deep into banksia flowers.

What adaptations do hairpin banksias have to their environment?

Hairpin banksias are well adapted to the sandy soils in which they grow. They have special proteid roots that are efficient at absorbing the low levels of water and nutrients that are available in the soil. Proteid roots are roots with many small rootlets. The leaves of hairpin banksias are narrow and hard which minimises water loss.

Hairpin banksias have woody enclosed fruits which protect their seeds from foraging animals.

Like other  banksias, hairpin banksias are well adapted to surviving fire events. After fire, leaves re-sprout from special ‘back up’ buds called epicormic buds found beneath the bark of the trunk. Some varieties of hairpin banksias have lignotubers which are woody swellings at the base of the plant which contain buds which sprout when the stem above ground is killed.

During a fire event the seed follicles of hairpin banksias open and release their seeds. The seeds are carried by the wind and drop to the ground to germinate in the ash-bed.

Seeds are released from the follicles of a banksia cone which open from the heat of a bushfire.

How do hairpin banksias reproduce?

Hairpin banksias rely on pollinators for their reproduction. Pollinators include native bees, birds such as spinebills and honeyeaters, and small mammals, such as brown antechinuses and ring-tail possums. The pollinators help transfer pollen between the flowers of different trees.

When the banksia flowers are pollinated they form woody seed pods called a follicle.

Fire, drought or plant stress cause the follicles to open and release seeds. During a bushfire the seeds drop to the ground and germinate in ash-rich soil clear from other plants which would otherwise compete for sunlight and water. Because of the relationship between fire and seed release it is important to prevent bushfires from becoming too frequent so that the new seedlings have an opportunity to grow into adults and produce seeds of their own.

In the absence of fire the follicles also release seeds to the ground when they become very dry or when other parts of the tree are dying.

Some of the follicles of this hairpin banksia cone have opened.

How are hairpin banksias used by Aboriginal Peoples?

Hairpin banksias are a source of food for Darug Peoples. The sweet-tasting nectar can be eaten by directly sucking it from the flower or soaking the fresh banksia flower in water to make a sweet drink.

Nectar-rich hairpin banksia flower

Eucalypt forest digital book

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Written by teachers, Eucalypt Forest is an exciting digital book which explores the beautiful natural environment of the Australian eucalyptus forest.

Learn about the interactions between plants and animals in the forest and how people can interact with and care for these special natural areas.

Containing a suite of interactive activities, videos and beautiful images, this book will encourage you to go out and explore your local eucalypt forest.

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