Ex-situ Wetland Plant Project

As part of Saving Oxford’s Wetland Wildlife, we’re collaborating with Oxford Botanic Garden, expert Judy Webb and the local community to help bring rare wetland plants back from the brink…

Oxford is a critical area for freshwater biodiversity, and ranks in importance alongside well-known areas such as the Lake District, the Norfolk Broads and the New Forest. The area supports rare and important wetland plant species such as Creeping Marshwort, Fen Violet, Greater Water-parsnip and Water Violet (you can read more about these species here). However, these species are only just clinging on in the Oxford area, with threats such as pollution, lack of suitable management and climate change posing very serious risks to remaining populations.

Creeping Marshwort is a Critically Endangered wetland plant.

As part of Saving Oxford’s Wetland Wildlife, Freshwater Habitats Trust has been collaborating with Oxford Botanic Garden and local expert Judy Webb to establish an ex-situ wetland plant conservation project. The project involves the cultivation of some of Oxford’s rare wetland plant species, which, once they have reached a large enough size, are planted out at suitable receptor sites around Oxford. This helps to boost populations and, critically, increases the number of sites each species occurs at. This kind of work is vital to prevent these species from going extinct, especially in the face of climate change.

Greater Water-parsnip (Sium latifolium) in flower.

So far, Greater Water-parsnip and Creeping Marshwort have been planted out as part of this project. Fen Violet, another endangered plant, was also planted out experimentally as part of a university project in 2015 on one receptor site, and has miraculously survived (Judy Webb was involved with this work). All three species are doing well so far at their receptor sites, which is excellent news, and practical management work funded by TOE was undertaken in July 2020 at several sites around Oxford ready for the planting out of some more Greater Water-parsnip plants in summer 2020.

Volunteers planting out Greater Water-parsnip at Cutteslowe Meadow in 2019. The plants were protected by a deer-proof fence.

The ex-situ conservation project was expanded in summer 2020 to include four more species of rare wetland plant: Water Violet, Frogbit, Marsh Stitchwort and Common Bladderwort. Staff at Oxford Botanic Garden are currently working on propagating these plants, and will hopefully have some Marsh Stitchwort and Common Bladderwort ready for planting out in summer 2021. Additionally, Freshwater Habitats Trust is in the process of establishing two ‘Species Conservation Hubs’ in Oxford to involve the local community with the conservation of Oxford’s wetland plants and raise awareness of Oxford’s freshwater heritage. We’ll have more to report on that soon!

Fen Violet (Viola persicifolia) in flower.

Fen Violet, Creeping Marshwort and Greater Water-parsnip in propagation at Oxford Botanic Garden.