Aristotle University of Thessaloniki: Ιnvader plant species spreads rapidly and threatens protected areas

An alien species, a plant invader that was named “German” is spreading rapidly displacing the local species and threatening protected areas while the fight against it is extremely difficult because the plant is working as a Hydra.

Professor in the Biology department of Aristotle University of Thessaloniki Nikos Krigas has covered thousands of miles of the rural road network and the motorways in order to locate and recorde the spread of the Solanum elaeagnifolium, a plant of American origin that is one of the most dangerous invaders worldwide.


“The plant follows the road networks because its round grains are drifted by the passing vehicles and spread rapidly,” he said.

The plant was initially spotted in 1927 in Thessaloniki and was imported probably with goods that came from the US. In 1930 it started growing in the city and during WWII the locals named it “German” because it spread everywhere.
According to an urban myth, the German occupiers brought it in Greece to feed their mules, something that is not true because the plant is poisonous, said Krigas adding that in 1950 the plant made its first appearance in Athens.
The plant does not have any natural enemies in Greece. On the contrary in America there are insects that eat its flowers.

In his study, professor Krigas found that the recorded populations of this species increased by 1,750 percent and 10 percent of Natura 2000 protected network has been invaded. “The natural ecosystems with structured societies when not disturbed appear to work as a barriers against the invaders. “A strong and broad programme with pesticides and constant uprooting must be applied against the invader. The most important is to be aware the the bigger the human intervention on the ecosystems the weaker they became in the invasion of the solanum elaeagnifolium,” said professor Krigas.