The Express, UK
June 2, 2005

1 Rhododendron (Rhododendron ponticum). Introduced from Armenia and
Turkey in mid-1700s as ornamental plant. Has now reached pest status.

2 Giant hogweed (Heracleum mantegazzianum). Introduced from South
West Asia in late 1800s. Contact with skin can cause severe irritation.

3 Spanish bluebell (Hyacinthoides hispanica). Threatens our native
bluebell species.

4 Japanese knotweed (Fallopia japonica). An indestructible weed
introduced in the mid-19th century. It is the most pernicious weed
in Britain.

5 Few-flowered leek (Allium paradoxum). From the Caucasus region.
Invasive woodland plant is spreading rapidly, especially in southern

6 Himalayan balsam (Impatiens glandulifera). Often found along

It can outgrow other species, stopping native plants from thriving.

7 False-acacia (Robinia pseudoacacia). From North America. Its
suckering can become a serious problem.

8 Parrot's-feather (Myriophyllum aquaticum). This South American
plant is mostly found in shallow ponds.

9 Water fern (Azolla filiculoides). From North and South America,
it is able to survive harsh British winters and can rapidly exclude
all competitors.

10 Australian swamp stonecrop (Crassula helmsii). Also known as New
Zealand pygmyweed, introduced in the early 20th century. Grows rapidly
in water, threatening native aquatic plants.