[1][2] It is a deciduous shrub or small tree growing to 3–4 m tall.

The shoots are zig-zagged, with a leaf and two stipular spines (one straight, one curved) on the outside of each kink.

The fruit is a dry woody nutlet centred in a circular wing 2–3.5 cm in diameter.

As suggested by the Latin name, the spiny branches of this shrub were thought to be used to make the crown of thorns placed on Jesus' head before his crucifixion.

It is viewed as an ornamental curiosity and is cultivated in some areas outside its native range, including Fiji.