Abstract
Knotweeds (Reynoutria Houtt.) are plants native to the Far East. Japanese knotweed was introduced from Japan to the unsuspecting West by the horticultural activities of Philippe von Siebold via his nursery at Leiden in the 1840s.
By 1854, the plant had arrived at the Royal Botanic Gardens in Edinburgh. The plants were then sold by a large number of commercial nursery gardens around the country.
Further vegetative spread followed naturally along watercourses. The knotweed is currently extremely persistant invasive plant.
There is also an important source of many bioactive substances which could be used in biomedicine. The article discusses biomedically relevant constituents and its pharmacological and toxicological properties.