May 17, 2013 Leave a comment In January this year, large parts
of southern Australia were ablaze with fierce bush fires, while
most of the UK was covered in snow. Half a world away from each
other, and at one point nearly 40ºC apart, there aren’t too many
similarities to be drawn between the two locations. And yet,
there is a water weed, Crassula helmsii, that survives happily
in both extremes – and in the UK, where it has been introduced,
this adaptability is proving extremely problematic. Crassula
helmsii, also known as Australian swamp stonecrop or New Zealand
pygmyweed, is a small semi-aquatic plant in the Crassulaceae
family. As its common name implies, this low-growing succulent
originates from the antipodes, but was introduced to Britain
from Tasmania almost 100 years ago. Initially sold by garden and
aquatic centres as an oxygenating plant, by the 1950s it had
established in the wild, and from there it has spread to
numerous ponds, lakes and waterways throughout the UK.