Eucalypt of the year 2026 – Our Eucalypt Home

Massive Marri blossoms are a keystone nectar and pollen resource across the Swan Coastal Plain, Darling Range, and surrounding forests and woodlands. Research by Dr Kit Prendergast and colleagues found that at least 81 species of native bees visit Marri flowers, often as the main—or only—plant they forage on, especially late in the season when other blooms have finished. Many bees also nest in small cavities and roots around Marri trees, and some even use its red sap (kino) in their nests.

The huge, urn-shaped ‘honky nuts’ hold seeds that are a major food resource for local parrots, including three threatened black-cockatoo species: the Carnaby’s (Endangered), Baudin’s (Critically Endangered), and Red-tailed Black Cockatoo (Threatened subspecies), as well as the Red-capped Parrot.

Whether straight and tall in forests or hunched and gnarled in woodlands, the Marri also provides the deepest and widest tree hollows in southwestern landscapes. The oldest, largest hollows are critical nesting habitat for black-cockatoos, some used over decades—but they can take centuries to form.

Other hollow users include the Critically Endangered Western Ringtail Possum, microbats, reptiles, and invertebrates.

Fallen Marri timber is an important habitat feature of Marri and Jarrah-Marri forests, contributing shelter and nutrients to the forest floor. Chuditch (Western Quoll) and Mardo (Yellow-footed Antechinus) nest and shelter in large Marri logs, while Quenda (Southern Brown Bandicoot) and Western Death Adders rest camouflaged in the thick leaf litter. Sadly, the essential goods and services Marri provides are under pressure from land-clearing, as well as climate-driven fire, drought and borer attacks. Protecting old trees safeguards food, shelter, and pollinators for the whole forest.

Those mysterious squiggles on scribbly gum bark aren’t graffiti, nor the bulletin boards of May Gibbs’ gumnut babies — they’re the work of tiny moth larvae.

The female Scribbly Gum Moth (Ogmograptis spp.) lays her eggs under the bark of a scribbly gum in autumn. Under the protective bark, the larvae are protected from the winter chill, and tunnel in the growing wood, feeding on scar tissue the tree produces as it heals. The trails start out as tiny scratchings, and widen as their creator grows. When the old bark is shed the following summer, the larvae fall into the leaf litter to pupate and their winter wanderings are revealed.

Thanks to scientists at CSIRO, at least 14 species of scribbly gum moth are known, and the marks only appear where these insects occur — mostly across eastern Australia.

Sydney Scribbly Gum is one of several trees famous for these patterns, along with Inland Scribbly Gum (Eucalyptus rossii) and Narrow-leaved Scribbly Gum (Eucalyptus racemosa).  Scribbly gum moths also use other eucalypts, including Snow Gums. This is why you can spot scribbles on gums in Tasmania, where none of the three species of ‘Scribbly Gum’ grow.

Beyond their iconic artwork, these trees support important bushland food webs. Their simple white flowers feed insects, honeyeaters and flying-foxes, their leaves support Koalas and herbivorous insects, and older trees develop hollows used by parrots, possums and microbats.

It’s impossible to pass an ironbark with that thick, dark, rugged bark and pendulous grey-green foliage and not be impressed.

Unlike smooth-barked gums, the ironbarks retain their bark, building a thick protection against fire and sap sucking insects and mammals. Those deep furrows in the tough bark provide shelter for foraging lizards and invertebrates and make it easy for predators like the Lace Monitor to scale the trunks and seek out nests full of eggs.

Winter flowering means that the true magic of this species is on show during winter. When so much else falls silent, the Box-Ironbark forests come alive.

During these colder, darker months, the Mugga Ironbark provides essential food for critically endangered Swift Parrots and Regent Honeyeaters. It is also an important food tree for flying-foxes, especially the Grey-headed Flying Fox.

In turn, these animals are significant pollinators of the species and other ironbarks.

Flying-foxes, Swift Parrots, and Regent Honeyeaters are nomadic, traveling far and wide between patches of flowering trees. This helps the trees send their pollen, and therefore, their genetic material, further afield to pollinate more distantly related trees. Pollination between distantly-related individuals (called ‘outcrossing’) creates stronger offspring that are more vigorous and more likely to survive. It enhances genetic diversity throughout the ironbark’s range, which is important for the long-term survival of the species.