England Releases Attack Fungus Against Himalayan Invaders

Experts are releasing a type of rust fungus across England and Wales in a combined inter-governmental and environmental group effort to hunt down and eliminate an invasive species that has been choking waterways and outcompeting native flora.

The invader, called Himalayan balsam (Impatiens glandulifera), is a shallow rooted species that is well known for its aggressive and impatient tendencies when it comes to spreading seeds. Its seed capsules split open explosively, scattering seeds in a wide arc in the hopes that they hit flowing water - where they can find new riverbanks to invade.

The plant, which looks like pleasant pink flower, was introduced into the United Kingdom as a garden plant back in 1839. However, without any natural competitors in the region, the plant began to cover more than an eighth of all the riverbanks in England and Wales.

This is hugely problematic not just for native floral species that it handily outcompetes, but also for the waterways themselves.  According to CAB International (CABI), formally the Commonwealth Agricultural Bureaux, the balsam bullies helpful flora away from the riverbanks that they have conquered. The result is escalated erosion in these areas, as the shallow roots of the Himalayan plant alone (designed for dripping rock and shallow soil) are not enough to hold loose earth in check.

Now this unassuming invader may finally meet its match. At the start of this month, CABI began releasing a fungus that specifically targets the Himalayan balsam without harming the 84 other main plant species that are found along the affected riverbanks - which include some of the United Kindom's ornamental and economically important plants.

"The rust, a Puccinia species, is an autoecious, macrocyclic (completing its entire life cycle on a single species), five spore staged rust fungus which infects the stem and leaves of Himalayan balsam throughout the growing season," the organization reported. "We have now completed all of the safety testing and shown that the rust is highly specific to Himalayan balsam," they added, and will now being moving on to letting this attack dog (er... fungus) loose.