Grass trees aren't a grass (and they're not trees)

  • Written by John Patykowski, Plant ecologist, Deakin University

Sign up to the Beating Around the Bush newsletter here, and suggest a plant we should cover at batb@theconversation.edu.au.

Grass trees (genus Xanthorrhoea) look like they were imagined by Dr Seuss. An unmistakable tuft of wiry, grass-like leaves atop a blackened, fire-charred trunk. Of all the wonderfully unique plants in Australia, surely grass trees rank among the most iconic.

The common name grass tree is a misnomer: Xanthorrhoea are not grasses, nor are they trees. Actually, they are distantly related to lilies. Xanthorrhoea translates to “yellow flow”, the genus named in reference to the ample resin produced at the bases of their leaves.

All 28 species of grass tree are native only to Australia. Xanthorrhoea started diversifying around 24-35 million years ago – shortly after the Eocene/Oligocene mass extinctions – so they have had quite some time to adapt to Australian conditions.

Wander through remnant heathland or dry sclerophyll forest, particularly throughout the eastern and south-western regions of Australia, and you’ll likely find a grass tree.

Grass trees aren't a grass (and they're not trees) CC BY Perfectly adapted to their environment Xanthorrhoea are perfectly adapted to the Australian environment, and in turn, the environment has adapted to Xanthorrhoea. Let’s start the story from when a grass tree begins as a seed. After germination, Xanthorrhoea seedlings develop roots that pull the growing tip of the plant up to 12cm below the soil surface, protecting the young plant from damage. These roots quickly bond with fungi that help supply water and minerals. Once the tip of the young plant emerges above ground, it is protected from damage by moist, tightly packed leaf bases, although shoots may develop if it is damaged. The leaves of Xanthorrhoea are tough, but they lack prickles or spines to deter passing herbivores. Instead, they produce toxic chemicals with anaesthetising effects. All Xanthorrhoea are perennial; some species are estimated to live for over 600 years. Most grow slowly (0.86 cm in height per year), but increase their rate of growth in response to season and rainfall. The most “tree-like” species grow “trunks” up to 6 metres tall, while trunkless species grow from subterranean stems. Grass trees don’t shed their old leaves. The bases of their leaves are packed tightly around their stem, and are held together by a strong, water-proof resin. As the old leaves accumulate, they form a thick bushy “skirt” around the trunk. This skirt is excellent habitat for native mammals. It’s also highly flammable. However, in a bushfire, the tightly-packed leaf bases shield the stem from heat, and allow grass trees to survive the passage of fire. Grass trees aren't a grass (and they're not trees) Fire burns the outside leaves but the centre survives. John Patykowski, Author provided Xanthorrhoea can recover quickly after a fire thanks to reserves of starch stored in their stem. By examining the size of a grass tree’s skirt, we can estimate when a fire last occurred. It can take over 20 years before a grass tree produces its first flowers. When they do flower it can be spectacular, producing a spike and scape up to four metres long advertising hundreds of nectar-rich, creamy-white flowers to all manner of fauna. Flowering is not dependent on fire, but it stimulates the process. The ability of grass trees to resprout after fire and quickly produce flowers makes them a vital life-line for fauna living in recently-burnt landscapes. Grass trees provide food for birds, insects, and mammals, which feast on the nectar, pollen, and seeds. Beetle larvae living within the flower spikes are a delicacy for cockatoos. Invertebrates such as green carpenter bees build nests inside the hollowed out scapes of flowers. Small native mammals become more abundant where grass trees are found, for the dense, unburnt skirt of leaves around the trunk provides shelter and sites for nesting. Indigenous use of grass trees For Indigenous people living where grass trees grow, they were (and remain) a resource of great importance. The resin secreted by the leaf-bases was used as an adhesive to attach tool heads to handles and could be used as a sealant for water containers. This valuable and versatile resin was an important item of trade. The base of the flowering stem was used as the base of composite spear shafts, and when dried was used to generate fire by hand-drill friction. The flowers themselves could be soaked in water to dissolve the nectar, making a sweet drink that could be fermented to create a lightly alcoholic beverage. When young, the leaves of subspecies Xanthorrhoea australis arise from an underground stem which is seasonally surrounded by sweet, succulent roots that can be eaten. The soft leaf bases also were eaten, and the seeds were collected and ground into flour. Edible insect larvae residing at the base of grass tree stems could be collected. Honey could be collected from flower stems containing the hives of carpenter bees. European exploitation European settlers were quick to clue onto the usefulness of the resin , using it in the production of medicines, as a glue and varnish, and burning it as incense in churches. It was even used as a coating on metal surfaces and telephone poles, and used in the production of wine, soap, perfume and gramophone records. Grass trees aren't a grass (and they're not trees) The versatile resin had been used in everything from medicine to gramophones. John Patykowski, Author provided Resin can easily be collected from around the trunk of plants, but early settlers used more destructive methods, removing whole plants on an industrial scale. The resin was exported worldwide; during 1928-29, exported resin was valued at over £25,000 (equivalent to A$2 million today!). We still have much to learn about grass trees. Current research indicates an extract from one subspecies can be used as a cheap, environmentally-friendly agent to synthesise silver nanoparticles that are useful for their antibacterial properties. Threats to grass trees Many of the oldest grass trees have been lost to land clearing, illegal collection, and changes to fire regimes. It’s vital we care for those remaining. Grass trees are particularly sensitive to Phytophthora cinnamomi, a widespread plant pathogen that is difficult to detect and control, and kills plants by restricting movement of water and nutrients through the vascular tissue. Growing native plants can be a wonderful way to contribute to the conservation of genetic diversity, and attract native fauna into your garden. Grass trees certainly make an interesting conversation plant! Read more: It's hard to spread the idiot fruit They can easily be grown at home, provided they’re sourced from a reputable supplier. The best way is to grow from seed, but patience is required as growth can be slow. Despite being relatively hardy, grass trees do not like being moved once large or established, so translocation of plants is not advised. In my opinion, the best way to see grass trees in their true splendour is to visit them in their natural habitat.

Authors: John Patykowski, Plant ecologist, Deakin University

Read more http://theconversation.com/grass-trees-arent-a-grass-and-theyre-not-trees-100531

Australia Today

How to build a knowledge-sharing organizational culture

Livia Bran, Content Manager at CYPHER LEARNING

The workplace of today is made up of people belonging to up to five generations. Each and every one of them knows things that can keep their organizations moving forward and considering the rise of the knowledge economy and how things might evolve in the future, a knowledge sharing organizational ...

Read more

Report recommends overhaul of My Health Record, but key changes not supported by Coalition

Robert Merkel, Lecturer in Software Engineering, Monash University

The opt-out period for My Health Record closes on November 15.ShutterstockThe Senate Standing Committee on Community Affairs report into the My Health Record system was released last Thursday. It has recommended several substantial changes to the way My Health Record operates that attempt to address...

Read more

Chocolate Labradors die earlier than yellow or black, and have more disease

Paul McGreevy, Professor of Animal Behaviour and Animal Welfare Science, University of Sydney

ShutterstockChocolate-coloured Labrador retrievers have, on average, 10% shorter lives than black or yellow Labradors, according to a study we co-published today in Canine Genetics and Epidemiology. Ear infections and skin diseases are also more common in chocolate Labradors than non-chocolate Labra...

Read more

Decoding the music masterpieces: Rossini's opera, Otello

Peter Tregear, Honorary Principal Fellow, University of Melbourne

Othello and Desdemona, Henri Jean-Baptiste Victoire Fradelle, circa 1827.Wikimedia, CC BY-SAIf you attend Rossini’s opera Otello (1813) expecting something close to the structure and poetry of Shakepeare’s original – as Lord Byron did when he went to a performance in Venice in 1818...

Read more

Why children in institutional care may be worse off now than they were in the 19th century

Nell Musgrove, Senior Lecturer in History, Australian Catholic University

National apologies for abuse are important, but children in institutional care also need better support transitioning to adulthood.ShutterstockPrime Minister Scott Morrison’s national apology to the victims of child sexual abuse was a moment of reckoning for the government – an admission...

Read more

Holidays & Travel

Adhari Park: Why is it one of the must-visit sites in Bahrain?

Despite its small area that does not exceed the 1,000 square kilometers mark, the Kingdom of Bahrain is known for being rich of touristic sites and attractions. Bahrain comprises destinations...

Exciting Off Road Adventures In Western Australia

Western Australia has long been a top destination for off roading enthusiasts from all across the world. One look at some of the top off road destinations on offer in...

Things to Do and See in Ballina, Australia

The intricate coastline of New South Wales is renowned for its sumptuous, decadent beaches, hidden resorts and secret camping spots. A long and slow ride down the winding highway that...

Guide to Travel Necessities for 2018

Sure, it sounds like quite an adventure to hit an open road with nothing but a one-way ticket and an open mind, but the harsh reality is – you won’t...

Top Sightseeing Spots in New Zealand

New Zealand is one of the most fascinating locations for anyone to visit in the world. After all, it’s a place with a variety of unique landscapes, but it isn’t...

Must-Pack Items for a Travel Blogging Boss

As a travel blogger, you get to see and explore so many wonderful destinations and meet various interesting people, but before you embark on a new adventure you need to...

Luxury Camping Adventures Around the World

Perhaps in direct response to the dominance of technology in the modern world, many travelers are feeling a strong draw towards nature. While some are able to fully embrace their...

Dredging works underway Plantation Island

Tourists and workers travelling to popular tourist destination Plantation Island, Fiji, are set to benefit from safer access when marine channel dredging is completed at the end of June 2018...

Top 5 Tips for Traveling With Dogs

Travelling with your dog can be thrilling, but sometimes it can turn into a real nuisance. Unless you know how to properly restrain the pooch, whether it’ll be able to...

Fashion & Beauty

Summertime skin

Summertime skin: the water based and nutrient-rich after sun gel-cream providing more antioxidant support than your traditional aloe While summer might mean spending days on end lapping up the glorious sunshine...

Groom To Do List

Sorry Aussie Men, you no longer just pay for the alcohol, flowers and marriage license. Times have certainly changed. Wedding Expert shares what Australian Grooms are now expected to do before...

Simple Secrets To A More Confident Smile

We all know just how important first impressions are. After a handshake, what’s one of the first things people will notice about you? It’s your smile. A friendly smile is...

Improve Your Body Confidence and Feel Great

No matter how good you feel about yourself, sometimes you just can’t help but see a few little flaws that seem gigantic to you and make you feel self-conscious. Whether...

First-Timer Tips For Your First Lip Filler Appointment

Getting injectable lip fillers can be a quick and effective way to plump up your smile with minimal drama. They’re a cost-effective and safe way to boost the natural shape...

The Most Common Skin Conditions and How to Deal with Them

We often underestimate the importance of our skin, but as the largest organ in our body, and our primary layer of defense, it is constantly affected by many environmental factors...

HEALTH

The Most Stressful Life Events and How to Deal with Them

Stress can be defined as mental or emotional tension caused by negative or challenging circumstances. It’s usually some sort of change that creates emotional turmoil we cannot cope with appropriately...

Is It Possible to Remove Moles Without Surgery?

Moles – everyone has them but not everyone wants to live with them. Fortunately, advances in cosmetic surgery have made it possible to easily remove any skin lesions that you are...

Tips for Women of Every Age: How to Stay Healthy and Fit

As we women age and grow old, our lives change from decade to decade. We’re struggling with college in our 20s, we’re trying to balance family and career through 30s...

Virectin Reviews and Results (LATEST) - Honest Review

Virectin is a potent, natural male enhancement supplement, recommended to all those who are interested in improving their sexual performance. According to the manufacturers, it can provide a positive effect...

How to Choose the Best Lasik Surgeon?? It’s as easy as it can get!

Whether you have had a vision problem since childhood, or you have developed one recently, eye surgeries are the answer to all your problems. It can be anything, ranging from...

Laser Liposuction: The Myths and Facts

Laser liposuction is a revolutionary new way to get rid of unwanted fat without the downtime experienced with traditional liposuction. This procedure offers a number of amazing benefits and is...

LIFE STYLE

5 Tips to Properly Plumb Your Vehicle

One of the greatest problems when it comes to plumbing your vehicle lies in the fact that it’s not something that most people care to think about until it becomes...

5 Things That Every Lady Should Know About Her Car

Being a woman has nothing to do with whether you know a thing or two about cars. Of course, it’s perfectly fine that you’re not interested in detailed car mechanics...

Is Your Mattress Firm Enough?

The word “firmness” is often used in relation to mattresses. Mattress manufacturers incorporate different materials into their products to increase or decrease its firmness, retailers rate their mattresses on a...

Should You Repair Or Replace Your Air Conditioning Unit?

Whenever the summer arrives to the hilt and you feel that your air conditioning isn’t up to the mark, there is always one question that pops up into your mind...

6 Rug Trends That Will Boost Style and Comfort in Your Home

If you want to break up that boring and colorless look of your home, one of the easiest and quickest ways is to throw in a rug! Check out these...

Put your problems to rest with Antenna Genie

When the idea of television was first being tested, Darryl Zanuck of 20th Century Fox famously remarked that “no one would want to stare at a plywood box every night”...

FOOD & DINING

Morning greens: the breakfast skincare regime

It’s safe to assume that most Aussies fail to eat enough greens. Although this was momentarily resolved with the rise and popularity of the green juice movement, the lack of...

Best Hidden Gem Hong Kong Restaurants

You finally find yourself enjoying the endless beauties of China and this fascinating city. In a place with so much variety, all your senses will be wide awake, and your...

JOHNNY DI FRANCESCO NAMED OFFICIAL AMBASSADOR OF EAT STREET MELBOURNE

Johnny Di Francesco, world champion pizzaiolo and owner of Melbourne’s Gradi Group of restaurants, is excited to announce he has been named official ambassador for Eat Street Melbourne 2018. As Ambassador...

The best Mother's Day gift EVER!

Whether it’s to celebrate a special occasion, or just wind down at the end of a long day, there’s nothing much better than pouring yourself a glass (or two…) of...

Sing for Your Supper at Chargrill Charlie’s

To celebrate the final curtain call of the Barden Bellas, Chargrill Charlie’s is giving you the chance to Sing for your Supper! Show off your best acapella vocals to win...

MAKE IT WINE TIME, ANY TIME

Whether it’s to celebrate a special occasion, or just wind down at the end of a long day, there’s nothing much better than pouring yourself a glass (or two…) of...