Marrubium vulgare (white horehound or common horehound) is a flowering plant in the mint family (Lamiaceae). Horehound often occupies disturbed or overgrazed ground; it is highly unpalatable to livestock.
Horehound grows in hard soils which are low in organic matter and in soil bacteria. It may indicate high levels of Chlorine in soil.
In New Zealand efforts are being made to control its spread with biocontrol measures using the horehound clearwing moth Chamaesphecia mysiniformis and the horehound plume moth Wheeleria spilodactylus that could eat their way through many plants