Invaders par excellence

“Hawkweeds are incredibly successful invaders. These hardy perennials tolerate a huge range of conditions including snow and poor soils. They are very fecund, with summer thistle-down seeds borne far on winds, animals and vehicles and winter tolerant stolons converting individual plants into dense mat-like colonies. And they indulge in underground chemical warfare, secreting chemicals that deter the roots of other plants. Their ecological devastation is horribly evident around the world. In New Zealand, mouse-ear hawkweed has completely displaced extensive areas of alpine tussock grasslands in the South Island.”

Source: Blog of the Invasive Species Council