Story: Cotton-covered seed pods from the Eastern cottonwood and a variety of poplar trees are responsible for the white blanket covering some city streets, especially tree-lined ones in Outremont, Mile End and Plateau Mont Royal. "It's absolutely incredible," said John Watson, the forest operations manager at the Morgan Arboretum on McGill University's Macdonald campus in Ste. Anne de Bellevue.
Expert: Prof. Benoît Côté, McGill Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences
Source: Montreal Gazette: http://www.montrealgazette.com/Technology/white+stuff/1722375/story.html