India, Oct. 28 -- In 1862, President Abraham Lincoln appointed Thomas Hogg U.S. marshal to Japan, and over the following years, Hogg sent plants home to his brother James, who ran a nursery in the Yorkville section of Manhattan. One of them was Japanese knotweed. A 2017 paper in the Journal of the Torrey Botanical Society by Peter Del Tredici of Harvard University's Arnold Arboretum pieced together how the plant reached North America.

Del Tredici found articles from 1868, 1872, and 1875 that point to three separate introductions during the 1860s. Two came from Europe, and one arrived directly from Japan through the Hoggs. In his 1875 article, James Hogg said the plant had reached him seven or eight years earlier, placing its arrival arou...