Well who would have thought it – we have our very own, special, ‘Haringey’ knotweed – Fallopia × conollyana (Haringey knotweed or railway-yard knotweed). Discovered (‘’new to science’’) in 1987 by David Bevan, growing in Railway Fields, a local Nature Reserve and a Site of Borough Importance for Nature Conservation Grade I, it is a cross between the Japanese Knotweed and the Russian vine and seems to have stabilised as a new plant deserving its own special name. Actually this type of knotweed cross is not unique to Railway Fields but we have been first to name it. Always take any sign of knotweed in your gardens very seriously and call in the experts. Nothing less will do against this incredibly invasive and pernicious plant, brought to us courtesy of Victorian garden enthusiasts who were thrilled at how well it did in our country.
http://www.archive.bsbi.org.uk/Wats23p539.pdf