The Australian tribe of grasses, Triodieae or ‘spinifex’, was well known to the early explorers of the continent’s centre. The tough sharpened leaf blades of this ‘porcupine grass’ were a dreaded obstacle to the adventurers’ vain pursuit of fertile lands and inland seas - a real Australian ‘thorn in the side’. For most, the endless spinifex grasslands symbolised a harsh and monotonous, if not hostile Australian desert, a place to heroically endure rather than celebrate.

Source: Jim Mant, Australian National University

The hummock grasses in the genus Triodia is said to dominate over 20% of Australia's mainland, growing on low nutrient soils found in sand plains and rocky ranges of the arid centre, as well as on rocky outcrops along the coasts.

Spinifex grasses can be divided into two groups known as ‘hard’ and ‘soft’ spinifexes.

The main difference is that the hard spinifex group does not contain resin, usually forming dense circular hummocks of rigid spiny leaves. They sometimes grow outwards with age into rings measuring 2-3 metres across, usually with a bare or dead centre.

The soft spinifexes are less densely packed, have less spiny leaves and form a continuous cover like tussock grasses. They also frequently exude sticky resin from the stems and leaves, contributing to the intensity of some of the outback grass fires. The sticky resin also collect to the underside of motor vehicles that drive through this type of spinifex grass and have been known to cause the vehicles to catch alight under certain circumstances.