smartweed
/ˈsmaɝtwiːd/Definitions
1. noun
a perennial herb of the buckwheat family, Polygonaceae, having clusters of small, greenish flowers.
“The smartweed growing in the nearby river was a nuisance to the fishermen.”
2. verb
to grow or spread rapidly.
“The invasive plant has been smartweed-ing its way across the entire continent.”