Carrot grass/Carrot weed (Parthenium hysterophorus)

Native herb of tropical America. Probably introduced into Sri Lanka in 1988 since it was first observed at the School of Agriculture at Vavuniya which Indian Peace Keeping Force occupied at that time. Now a widely spreading invasive weed of abandoned fields, waste lands, roadsides and cultivated grounds. The plant is toxic and can cause skin and respiratory system problems.

These plant were observed at a roadside location close to the Mathale town (7°27.769'N, 80°37.767'E)