NNNSI Priority Species - Have you seen any of them?

A Call for Data

The current focus of the Norfolk Non-native Species Initiative (NNNSI) is on invasive aquatic and riparian plant species. The following six species have been identified by stakeholders as being a high priority for action:

Australian swamp stonecrop
Japanese knotweed
Giant hogweed
Floating pennywort
Himalayan balsam
Parrot's feather

To facilitate more strategic and priority-driven management of invasive non-native species, the Initiative is gathering and collating data on the distribution of these species across Norfolk. If you hold records for these then please do let us know! In addition to these six priority species, the Initiative would welcome records on all invasive alien species found in Norfolk. For a full, categorised list of invasive non-native species of concern in Norfolk please click here.

 IF YOU HAVE SEEN ANY OF THESE 6 NON-NATIVE SPECIES PLEASE USE OUR ONLINE RECORDING FORM (LINKS BELOW) TO TELL US ABOUT YOUR SIGHTING(S).

FOR MORE INFORMATION ON EACH OF THE PRIORITY SPECIES SEE DETAILS BELOW THE ONLINE RECORDING FORM LINKS.



 

HAVE YOU SPOTTED ANY OF THESE 6 NON-NATIVE SPECIES?

The easiest way to send us information about the species you have seen is via our online form. Please select one of the three options below to send us your record:

 



(e.g. more than 20 records; including records of more than one species,
at more than one location and on several different dates 
- please send as excel spreadsheet where possible using our template)

DOWNLOAD THE NBIS RECORDING SPREADSHEET HERE AND THEN CLICK ABOVE TO EMAIL US YOUR RECORDS
 (or email nbis@norfolk.gov.uk)


 



 

THE 6 PRIORITY SPECIES.....SOME BASIC INFORMATION:

 

Japanese knotweed

 Description: Japanese knotweed is a tall herbaceous perennial. In the summer the plant has shield-shaped leaves and distinctive purple speckled stems, similar to bamboo stems in appearance. Dead stems remain throughout the winter, although these may be more difficult to identify.

Where to look: It is commonly found on brownfield sites and along river banks, although it can grow in almost any terrestrial habitat. Japanese knotweed does not produce seed in the UK, and spreads solely by vegetative means (fragments of the stem or root rhizome) so be careful not to accidentally introduce it to a new area!

ID Sheet https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=369

 

Himalayan balsam

Description: A tall, attractive, annual herb with explosive seed heads. In the summer and early autumn this plant is easily identifiable due to its distinctive purple-pink flowers, fleshy stem and characteristic leaves. Following dieback in October/November the plant is much more difficult to identify, with the dead stems often falling on the ground to leave hay like remains.

Where to look: Himalayan balsam grows prolifically along river banks and in other damp areas. In Norfolk it is frequently found in the Broads, and is also abundant along the River Wensum and River Bure.

ID Sheet

https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=33

 

Giant hogweed

Description: When fully grown giant hogweed can reach a height of up to five metres, with leaves up to three metres in length. The plant has large umbrella-shaped flowers which are white, or occasionally light pink, in colour. The leaves are serrated, with the stem being green with purple blotches and covered in sharp bristles. Throughout the winter the dead stems normally remain standing, which are easily spotted due to their height and distinctive shape.

Where to look: Giant hogweed is often found growing along river banks and on roadside verges.

WARNING: DO NOT TOUCH THIS PLANT! The sap of giant hogweed can cause severe blistering!

ID Sheet

https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=30

 

Floating pennywort

Description: Floating pennywort is an aquatic plant that can be found either free-floating or rooted. It has distinctive kidney-shaped leaves with a crinkled edge which can either be submerged or emergent. The plant forms dense mats of vegetation which commonly grow from a river bank, extending several metres out into the main body of the river. This plant does not flower in the UK.

Where to look: Floating pennywort is not common in Norfolk, although it is present in the River Waveney. It may be present in garden ponds, as it was first introduced to the UK by the horticultural trade.

ID Sheet

https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=31

 

Australian swamp stonecrop

Description: Australian swamp stonecrop (also known as New Zealand pygmyweed) can be submerged, emergent and terrestrial. It has small fleshy leaves arranged in opposite pairs, which radiate from a brittle, round stem. This plant does not produce viable seen in the UK.

Where to look: This plant is fairly widespread across Norfolk. It can be found growing in still or slow flowing water bodies, and frequently grows terrestrially around the edges of lakes or ponds.

ID Sheet

https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=360

 

Parrot’s feather

Description: Parrot’s feather has a large amount of distinctive, blue-green emergent growth above the water, making its identification relatively straightforward. The plants finely-divided leaves form whorls of 4-6 leaves, which radiate from a brittle stem. The plant does not produce seeds in the UK.

Where to look: Parrot’s feather is not common in Norfolk, currently being known at less than 40 sites. However, there is a significant risk of this plant being present in a large number of garden ponds, as it is still available to purchase from some retailers (usually sold under one of its pseudonyms). It can grow in still or slow flowing water bodies.

ID Sheet

https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=66