Pajuasteri – Symphyotrichum salignum

The common Michaelmas daisy was created for ornamental purposes as a cross between panicled aster (A. lanceolatus) and New York aster (A. novi-belgii), both of which are native to North America. The hybrid is assumed to have been created in Europe in the 1700s.The common Michaelmas daisy was introduced to Finland as an ornamental in the 1800s. The first escapee into the wild was recorded in Helsinki in 1875. Today, it grows in places in southern and central Finland, all the way up to Oulu in the north. It has spread quickly in the metropolitan area, particularly along the River Vantaa, in recent decades, as changes in land use have created new space for the plant to grow on riverbanks.The common Michaelmas daisy is also classified as invasive in Estonia, Latvia, Lithuania and Russia.