Bracken Fern

Occurring in temperate and subtropical regions in both hemispheres. (The extreme lightness of its spores has led to its global distribution.) Bracken is an aggressive colonizer of disturbed and other successional habitats and has been considered an invader of pastureland. It has been shown to be allelopathic (to produce compounds that inhibit the growth of other plant species) and can form dense monocultures. It is difficult to eradicate or control and, because it is toxic, renders such pasturage unfit for grazing.