I find it hard to think of a ‘more Australian’ image, at least in eastern and south-western Australia, than a stand of grasstrees with their immediately recognisable silhouettes.

The distinctive blackened trunks and skirt of leaves, from which grow enormously tall spikes glowing with thousands of little white flowers, say ‘Australia’ loudly and clearly to me. Often the setting is a landscape burnt in the previous summer, because fire can trigger a mass flowering.

Close to home, the slopes along the access road to Tidbinbilla Nature Reserve support one of the largest accessible colonies of grasstrees in the area. The hillside to the right on the descent to Lake George also has an impressive stand of them, but these are ‘rescue’ grasstrees, relocated from planned roadworks in the area.

There are about 30 species, and they are neither grasses nor trees, but giant lily relatives.

However, ‘grasstree’ is really the only widely accepted name for them – Xanthorrhoea, their formal name, is never likely to take off. I grew up in South Australia calling them yaccas, and still think of them as such, but it doesn’t mean much here. In past times, they were ‘blackboys’, but that is mercifully receding into history.

The trunks differ markedly from woody tree trunks and are formed from the bases of leaves that have since died as new ones grow above them and shade them out. They are embedded in resin which has set hard, making the trunk very solid and largely fire-proof. Within the core is a network of soft fibres that transport nutrients and water between the leaves and the roots.

In a fire, the leaves are burnt off, but at the base of each one is a leaf bud, protected from the fire’s heat by the leaf base. As soon as the sheltering leaf is removed, the new bud starts to grow, so the recovery of the plant after fire is very rapid.

Grasstrees flowering after a wildfire on the South Coast. Photo: Ian Fraser.

It is a myth that they only flower after a fire, though they do put on a particularly splendid display after they have been burnt. The flower spike can be well over three metres high in some species, including the local one, and may bear tens of thousands of tiny lily flowers which attract a wide array of pollinators 24 hours a day.

Locally, Sugar Gliders and many moth species come out at night (along with bats and owls, which prey on them), and by day there are butterflies, hoverflies and other flies, beetles, wasps, bees, small honeyeaters, big wattlebirds and friarbirds.

While not all the numerous flowers will be pollinated to form seeds, hundreds probably will.

Humans have relied on them for a variety of products for many thousands of years.

The resin makes an excellent adhesive when melted for gluing tool heads to handles. For this reason, the resin was also melted, formed into large lumps and traded across the country. The dried flower stalks were fashioned into spears or used as fire sticks. Grass trees were also the source of a variety of foods.

Big, nutritious moth larvae could be found at the base of the plant. Nectar was eaten from the flower stem by running leaves up through the flowers or soaking them in water, and flour was made from the crushed ripened seeds. The soft bases of the inner leaves could be eaten raw or cooked. The leaves could be woven into baskets or shelters.

A grasstree flowering spike contains tens of thousands of tiny lily flowers, which attract pollinators like this hoverfly. Photo: Ian Fraser.

After 1788, the newcomers to Australia learned from them and found their own uses as well.

Medicines (for both constipation and diarrhoea!), perfumes and varnishes were distilled from the resin and brake blocks for steel wagon rims fashioned from the trunks. It was even rumoured that in the earliest years of the 20th century, Germany imported large amounts of the resin for the explosives industry.

However, as always, the plants and animals that make Australia unique are worthy of our focus and appreciation for their own sake, not just because they have been useful. That certainly applies to the wonderful grasstrees.

Ian Fraser is a Canberra naturalist, conservationist and author. He has written on all aspects of natural history, advised the ACT Government on biodiversity and published multiple guides to the region’s flora and fauna.