Perfoliate Alexanders: An invasive alien?

Perfoliate alexanders
Perfoliate Alexanders (Smyrnium perfoliatum) Photo: Jo Parmenter

In the past few days, Jo has found two separate populations of this highly invasive alien plant close to the Wensum in Norwich. This is only the second record for VC 27 East Norfolk but seems to be spreading rapidly. James Emerson of NNNS has also been looking for it and discovered a further population at Whitefriars. Smyrnium perfoliatum is a Schedule 9 plant (meaning it is illegal to plant or otherwise cause to grow in the wild). Hitherto there hasn’t been much of it about in Norfolk and it has potential to spread along the woodlands of the Southern rivers. We don’t know how much of a nuisance it might make of itself here; however it is causing problems in south London where it is invading ancient woodlands. Kew are busy trying to eradicate it. http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=3303

perfoliate alexanders
Perfoliate Alexanders (Smyrnium perfoliatum) Photo: Jo Parmenter

Andrea Kelly at the Broads Authority has alerted her southern rivers team to keep an eye open for it.

Jo Parmenter and James Emerson 04.2019