African Boxthorn, Lycium ferocissimum, is a Weed of National Significance in mainland Australia. It’s a localised nuisance on Norfolk Island. Spines thick enough to penetrate car tyres can inflict painful puncture wounds in human flesh.
The photograph of Boxthorn covering slopes on the the Hundred Acres Reserve demonstrates both its ability to smother all desirable vegetation and also the need for very careful planning of control measures. Abrupt removal of the boxthorn would run the risk of irreversible soil erosion. However, boxthorn also tends to suppress the growth of grasses nearby and grasses are very good for protecting the surface of the soil from raindrop and wind erosion.