Spiny emex is an annual herb with a semi-prostrate growth habit.
The mostly hairless leaves are ovate to triangular in shape.
The inconspicuous flowers form into a burr about 7cm long with three thick spines
Source: NSW Weed Wise 2018, NSW Weed Wise, NSW Department of Primary Industries, accessed 11 February 2023, < https://weeds.dpi.nsw.gov.au/Weeds/Spinyemex>.