Non-native invasive plants

Stop the spread

Can you help us map non-native invasive plants across the River Thame catchment.

Non-native invasive plants out compete our native plants and, if left to their own devices, can take over whole river banks, streams and ponds. Without effective control methods they can quickly spread and recolonise areas after removal.

We need your eyes to help us map the locations of these non-native plants. This way we can effectively target areas to ensure they are removed for good.

If you are interested in surveying for non-native invasive species please email us at

Report a sighting

— Submit a sighting from home —

If you’ve seen a plant and want to report the sighting once you’ve got home please use our online form.

— Submit a sighting on the go —

To submit sightings when you’re out and about please download and use the Epicollect5 app on your smart phone. The app will access your GPS to record the location of the sighting so you must be nearby.

  • Download the Epicollect5 app onto your smart phone.
  • Search for ‘Thame Catchment INNS survey’ form and add to the app. The app will remember this and you’ll only need to add it once.
  • Press ‘add entry’ and follow steps to fill in form. Takes around 2-3mins
  • Upload entry and photos.

Non-Native Plant Species Identification Fact Sheets

Below are identification sheets for a selection of non-native invasive species that we are trying to map the locations of. These Identification sheets were produced by NNSS. For more information on non-native species and national projects to tackle them please visit the NNSS website.

New Zealand Pygmyweed (Crassula helmsii)

©Freshwater Habitats Trust

This work is possible thanks to the support of Thames Water.