Gorse (Ulex europaeus) was introduced to NZ from England sometime before 1835 for farm hedges.
A fast-growing, short-lived shrub, it thrives in NZ.
Its seeds spread and germinated on farmed land, forming impenetrable, spiny thickets.
Gorse was declared a noxious weed in NZ by Act of Parliament in 1900.
Farmers consider gorse a curse, but environmentalists like it because forest regenerates rapidly beneath it.