Invasive Plant Species - The List

The ‘knowns’ and ‘unknowns’ of invasive plants

Our ‘List of Invasive Plant Species’ Guidance Note is useful as a crib-sheet to determine the status of an individual non-native plant in each devolved administration, but also highlights some taxonomic changes surrounding a few plants (reference the guidance  footnotes).  

The most important one is for Japanese knotweed which, for several decades now, has been referred to by the latin name Fallopia japonica.  However, through scientific studies of plant morphology and genetics (phylogenetics), taxonomists recently re-assigned Japanese knotweed to the genus Reynoutria.  Clearly, this is now the ‘correct’ name for Japanese knotweed and it should be used where possible, but Fallopia remains the name in virtually all Government statutes and Guidance. At the PCA, we believe both can be used inter-changably for the time being ie. using one or the other, but always giving (at least once) Reynoutria japonica as the accepted, botanically correct, binomial.  

More about Japanese knotweed >>

The invasive ‘known unknowns’

This leaves us with a few ‘anomalies’ - the known unknowns - like buddleia and bamboo.  These are well-known garden escapers which are non-native AND invasive yet there seems to be little appetite within the Environmental organisations to give them any official status under the Wildlife & Countryside Act as it applies around the UK.  The PCA has lobbied the GB non-native species secretariat on this matter and we hope they will consider these and others at up-coming review meetings.