The question of weeds and the migration of plants is an interesting phase of botany. I have discussed this subject quite fully in several papers on weed migration.
Proceedings of the Iowa Academy of Science
©1930 Iowa Academy of Science, Inc.
Pammel, L. H.
"Some Weeds of Iowa, Florida, Lower Rio Grande Valley, Cuba and India Compared,"
Proceedings of the Iowa Academy of Science, 37(1), 143-149.
Available at: https://scholarworks.uni.edu/pias/vol37/iss1/28