The coastal banksia has its roots in ancient Gondwana

John Tann/Flickr, CC BY

Gregory Moore, University of Melbourne

If you fondly remember May Gibbs’s Gumnut Baby stories about the adventures of Snugglepot and Cuddlepie, you may also remember the villainous Big Bad Banksia Men (perhaps you’re still having nightmares about them).

But banksias are nothing to be afraid of. They’re a marvellous group of Australian native trees and shrubs, with an ancient heritage and a vital role in Australian plant ecology, colonial history and bushfire regeneration.

The genus Banksia has about 173 native species. It takes its name from botanist Sir Joseph Banks, who collected specimens of four species in 1770 when he arrived in Australia on board Captain Cook’s Endeavour.

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One of the four species he collected was B. integrifolia, the coastal banksia. This can be a small to medium tree about 5m to 15m tall. In the right conditions, it can be quite impressive and grow up to 35m.

It’s found naturally in coastal regions, growing on sand dunes or around coastal marshes from Queensland to Victoria. These can be quite tough environments and, while B. integrifolia tends to grow in slightly protected sites, it still copes well with sandy soils, poor soil nutrition, salt and wind.

In the right conditions, coastal banksia can grow to 35m tall.

From ancient origins

Coastal banksia – like all banksias – belong to the protea family (Proteaceae). But given the spectacular flowering proteas are of African origin, how did our Australian genera get here?

The members of the Proteaceae belong to an ancient group of flowering plants that evolved almost 100 million years ago on the southern supercontinent Gondwana. When Gondwana fragmented more than 80 million years ago, the proteas remained on the African plate, while the Australian genera remained here.

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The firewood banksia is bursting with beauty

The spikes of woody fruits on the Australian banksia, sometimes called cones, are made up of several hundred flowers. The flower spikes are beautiful structures, soft and brush-like. But with B. integrifolia, they are pale green, similar to the foliage, and can be hard to see within the canopy at a distance.

Up close, these fruit spikes can look quite spooky, almost sinister, especially when wasps have caused extensive gall formation. Galls are swellings that develop on plant tissues as a result of fungal and insect damage, a bit like a benign tumour.

Maybe this is what led May Gibbs to cast them as the baddies in her Gumnut Baby stories. While the galls may look unsightly, they rarely do serious harm to banksias.

Banksias were depicted as the Big Bad Banksia Men in May Gibbs’s Gumnut stories.
May Gibbs/The Northcott Society and Cerebral Palsy Alliance

Indigenous use

Given the fruit spikes of coastal banksia look like brushes, it’s not surprising Indigenous people once used them as paint brushes.

The flowers are very rich in nectar, which attracts insects and birds. If you run your hand along the flower spike you, like generations of Aboriginal people before you, can enjoy the sweet taste if you lick the nectar off your hand. You can also soak the flowers in water and collect a sweet syrup.

In the garden, B. integrifolia is wonderfully attractive to native insects, birds and ringtail possums. It’s easy to establish and, until it grows more than a few metres high, can be successfully moved and transplanted.

Coastal banksia doesn’t need fire to release its seed.

Unlike many other banksia species, coastal banksias don’t need fire to release their seed. For many Australian species, the woody fruits remain solid and sealed, and it’s only when fire comes through that they burn, dry, crack open and release their seed.

This can happen with B. integrifolia too, but in a garden setting the fruits will mature, dry and crack open and release the seeds, which germinate readily. This makes propagating coastal banksia easy work.

In touch with its roots

Perhaps one of the more important, but less obvious, attributes of B. integrifolia are its roots. These are a special type of root possessed by members of the protea family.

The roots form a dense, branched cluster, a bit like the head of a toothbrush, that can be 2-5cm across. They greatly increase the absorbing surface area of the roots, as each root possesses thousands of very fine root hairs.

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Proteoid roots can be very handy in sandy and other poor soils, where water drains quickly and nutrients are scarce.

These roots, also described as cluster roots, are often visible in a garden bed just at the interface of the soil with the humus or mulch layer above it. They’re very light brown, almost white, in colour.

Rainbow lorikeets love hanging around in banksias.
Flickr/Salihan, CC BY-NC-ND

B. integrifolia, like other banksias, also has the ability to take in nitrogen and enrich the soil, which can be very handy in soils low in nitrogen. It’s like a natural living and decorative fertiliser.

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Proteoid roots are unfortunately very well suited to the presence of Phytophthora cinnamomii (the cinnamon fungus). It causes dieback in many native plant species, but can be particularly virulent for banksias.

But B. Integrifolia is one of the more resistant species to the fungus. Promising experiments have been done on grafting susceptible species onto the roots of B. integrifolia to improve their rates of survival.

This could be important, as banksias have a role in bushfire regeneration in many parts of Australia, so the occurrence of the fungus can compromise fire recovery.The Conversation

Gregory Moore, Doctor of Botany, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.


The firewood banksia is bursting with beauty

File 20190301 22871 1dxrm0x.png?ixlib=rb 1.1

Gnangarra via Wikipedia, CC BY-ND

Rachel Standish, Murdoch University and Lauren Svejcar, Murdoch University

Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.

Firewood banksia is rugged and yet stunning. Short, stout and gnarled, it is often ignored by tree lovers. Indeed, it was commonly cut down and used as firewood in the early days of the Swan River Colony in modern-day Western Australia.

However, the flower spikes are stunning – showy and vibrant, dark pink-red in colour that becomes mixed with yellow as they open – and set against a backdrop of elegant twisted grey-green leaves. Each spike is composed of up to 6,000 individual flowers, and yet only a few become filled with seeds.

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The “cones” (these are not true cones like pine cones) are magnificent too – velvety chocolate brown, impressive in their woodiness, and expressive as the mouth-like follicles open to release their seeds. Symmetrical by turn and then messy by another turn, no other banksia species looks quite like it.

The Conversation

We admire firewood banksia for functional reasons too. Life on Western Australia’s sandplains is tough, especially in the heat of the summer. One of us (Lauren) knows this all too well, having spent hours on her hands and knees counting banksia seedlings for her PhD research.

Large seeds provide the seedlings with resources to grow exceptionally long roots to reach water deep in the sandy, nutrient-poor soils. It’s an adventure race for survival because roots need to tap the ground water before the arrival of the long, hot Perth summer.

Seedlings of a neighbouring banksia species, the slender banksia, can grow roots at a rate of up to 3.5cm per day!

The flower spikes begin as a dark pink-red and become red-yellow as they mature.
Photo by Lauren Svejcar

Uniquely Aussie

Banksia is a plant genus unique to Australia, named after the great botanical explorer Sir Joseph Banks. Banks travelled on the HMS Endeavour with James Cook on his first great voyage to the “unknown southern land”. The specimens Banks and his team collected formed the first scientific collections of Australian flora, now held at the Natural History Museum in London and the Royal Botanic Gardens in Sydney.

According to fossil records of pollen, leaves and cones, banksia species have grown in Australia for at least 60 million years making their lineage one of the oldest in Australia. Banksia have persisted through major climate shifts from wet to dry climates that occurred about 25 million years ago. Even the first banksia species were able to survive recurrent wildfire, owing to what botanist Alex George refers to as the “ruggedness” of their features. Banksia epitomise what it means to be Australian.

A woody ‘cone’ (infructescence) with seeds maturing inside swollen follicles. It is cheap for plants to produce wood in Australia because there’s plenty of sunlight, so why not offer your seeds total protection?
Photo Lauren Svejcar.

Some 20 years after Cook’s first voyage of the east coast came the discovery of the rich banksia flora on the south-west coast of Australia. Banksia grow in non-arid regions all over Australia, but most species grow only in Western Australia.

Surgeon-naturalist Archibald Menzies was the first explorer to see and sample the diversity of banksia species growing in the south-west near Albany. Our favourite banksia, the firewood banksia is named in his honour: Banksia menziesii.

Facing danger

While their experience of historic climate change and ruggedness may protect firewood banksia from Perth’s drying climate, ongoing habitat clearing makes them vulnerable to decline and has contributed to the banksia woodlands of the Swan Coastal Plain being listed as an endangered ecological community.

One of us (Rachel) played in banksia woodlands as a child, climbing the gnarly trucks of firewood banksia and collecting spent cones. Long before that, the Whadjuk Noongar collected flower spikes to make bush medicine. Having nature nearby is so important for people and for conservation. It is overwhelmingly sad that future generations of Perth may not be afforded this unique opportunity.

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Birds and insects love firewood banksia too. Birds are the primary pollinators of firewood banksia, no doubt attracted to the beautiful pollen-rich flowers. Interestingly, insects visit flowers more often than birds, but they are less effective pollinators.

Carnaby’s cockatoos feeding on firewood banksia.
Photo by Lauren Svejcar

The seeds are an important food source for the critically endangered Carnaby’s cockatoo. Hungry cockatoos often visit the firewood banksias that grow on our university campus in Perth’s southern suburbs. We count our lucky stars we get to watch while they squawk and feast, leaving when their tummies are so full that take-off is comical and there’s a mess of woody litter under the trees. It’s a blissful moment before the snarl of commuting traffic or the pull of work, connecting us to nature and to things bigger than ourselves.

Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.. Read previous instalments here.The Conversation

Rachel Standish, Senior Lecturer in Ecology, Murdoch University and Lauren Svejcar, PhD Candidate, Murdoch University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Myall Lakes National Park

Kevin's Daily Photo, Video, Quote or Link

It was my first official day of annual leave from work today and of course it had to start with a good sleep-in, which I might add I’m going to try and avoid doing for the entire period of my annual leave – just the first couple of days. I have been extremely tired, so a few sleep-ins will be helpful – for my health and well being you know. I’m sure you know what I’m talking about and agree with me entirely. I take your silence as tacit agreement. Thank you for that.

Myall Lakes National Park

Once I was up I thought I should do something – so the day wouldn’t be viewed as an entire waste. So a drive to Bulahdelah was on the cards via the Myall Lakes National Park and the Bombah Point Ferry. So that’s what I decided to do, after I thought through a few more possible options for…

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Yacaaba Headland Walk

Kevin's Daily Photo, Video, Quote or Link

I ran out of time yesterday to post about my walk up Yacaaba Headland and how I only just avoided being in a storm that was moving in. So today (it’s actually the 27th July 2012 as I type away) I must get two days of posts done, even if I slip this one in back in time, so to speak (as you can with the post time when posting).

BrunchSo I decided to do the Yacaaba Headland walk just before lunch and had lunch in the carpark, while reading the paper. Nothing too healthy – I tend to eat far too much junk when I’m on holidays. So it was a bacon & egg roll, as well as a couple of potato scallops and some chips (and coke of course) See Picture at Left. It was really brunch and I needed the energy boost to accomplish the walk. Sounds…

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