As you’ll know if you’re reading my book, I was quite delighted with the appearance of the spinifex grass that I saw growing everywhere in the Red Center—and that I would see so many other places in Australia. I described it as looking like “herds of golden hedgehogs.” Of course, the golden part depends on whether there has been rain or not, because new growth is green. But these grasses turn golden as they dry, turning their rounded hummocks a pale tan that contrasts nicely with the red earth.
I should add that I delighted in spinifex even as I learned to avoid it. When the grass dries, it rolls into sharp needles that can be uncomfortably prickly if you run into them. It is for this reason that spinifex is also sometimes called “porcupine grass.”
Interestingly, the spinifex grass of the Outback is not a member of the genus Spinifex. The genus Spinifex is a group of grasses found in sandy habitats along coastal beaches. The spinifex of the arid interior belongs to the genus Triodia. As happened so often in the New World (the Americas as well as Australia), travelers and exploreres picked up one name and stuck it on new things they encountered that were somewhat similar but not necessarily related.
Well those hummock grasses of the genus Triodia that had caught my attention in the Center are, in fact, the dominant vegetation of more than 20 percent of Australia. They occur in all states except Tasmania. However, there are 64 species that have been described thus far, so not every hummock of spinifex looks identical to the others, with variations in roundness and height being the most obvious differences.
Spinifex is classified as a hummock grass because it grows in a dense hummock, or dome shape. Even when there has been rain, the only green will appear on the outside of the hummock, protruding from the densely matted hummock of matted stems and dead leaves.
Many species of spinifex are extremely resinous—to the point that resin will actually drip down the stems and leaves on hot days. This resin was traditionally important among many Aboriginal groups, as it could be heated, molded, and used to attach spear points to shafts or repair work instruments. Even today, in a pinch, spinifex gum is used to repair leaking buckets or broken tools.
In the photo below, the spinifex shows much new, green growth—but it also clearly shows the rounded, hummock formation that is characteristic of this Outback grass.