Original sentence: The species status in the New World is uncertain: it is generally considered an exotic weed however there is evidence that the species was in Crawford Lake deposits (Ontario) in 1430-89, suggesting that it reached North America in the pre-Columbian era
Edited sentence: The species status in the New World is uncertain: it is generally considered an exotic weed; however, there is evidence that the species was in Crawford Lake deposits (Ontario) in 1430-89, suggesting that it reached North America in the pre-Columbian era