Greater water parsnip, Sium latifolium
Information on the plant available from Freshwater Habitats Trust (1) and FHT (2)
Judy's reports for the Oxfordshire Flora Group:
2018 pp 16-17 2019 pp 19 -20 2020 pp 16-18 2021 pp 18-19 2022 pp 20-23
Other rare species monitored by Judy
Judy is involved with the FHT's Ex-situ Wetland Plant Project
The FHT page 'Oxfordshire rarity gets a new home' refers to Judy's involvement in 2017 with GWP planting at Pinkhill Meadow
A short video, A Guided Walk at Cutteslowe Meadow, was filmed on 28 July 2020 by The Freshwater Habitats Trust.
In it Ellie Mayhew, Southern Project Officer, explains what the Trust is doing at Cutteslowe to best manage the site for freshwater wildlife
in collaboration with Oxford City Council, local expert Judy Webb, and others. See also the FHT's Cutteslowe Meadow page
Information on the plant available from Freshwater Habitats Trust (1) and FHT (2)
Judy's reports for the Oxfordshire Flora Group:
2018 pp 16-17 2019 pp 19 -20 2020 pp 16-18 2021 pp 18-19 2022 pp 20-23
Other rare species monitored by Judy
Judy is involved with the FHT's Ex-situ Wetland Plant Project
The FHT page 'Oxfordshire rarity gets a new home' refers to Judy's involvement in 2017 with GWP planting at Pinkhill Meadow
A short video, A Guided Walk at Cutteslowe Meadow, was filmed on 28 July 2020 by The Freshwater Habitats Trust.
In it Ellie Mayhew, Southern Project Officer, explains what the Trust is doing at Cutteslowe to best manage the site for freshwater wildlife
in collaboration with Oxford City Council, local expert Judy Webb, and others. See also the FHT's Cutteslowe Meadow page
12 Sept 2022 Professor Jeremy Biggs, CEO of the Freshwater Habitats Trust, replied to Judy Webb's tweet about the progress of greater water parsnip on a site in the Cherwell floodplain north of Oxford:
'Great job looking after what is becoming a remarkable site, with 'new' (2004) ponds now supporting populations of four regionally or nationally rare wetland plants (one natural colonist, three experimentally introduced) as part of work to protect freshwater biodiversity. The plants had survived the drought and were making good seed for collection - offered to the FHT and Oxford University's Botanic Garden for propagation. Scything and raking were also carried out that day by Oxford City Council's Thursday Conservation volunteers, now led by Judy Webb following the departure of the City Council's Carl Whitehead, who now works for Witney District Council. Photos in Judy's tweet |
12 June 2022 David Wilding of the RSPB visited Cutteslowe Meadow to learn about the introduction there of Greater Water Parsnip from Judy Webb and David Morris, Senior Plant Ecologist for the Freshwater Habitats Trust and Botanical Society of Britain and Ireland (BSBI) County Recorder for Oxfordshire. This was in preparation for the introduction of the plant to Otmoor in the summer of 2022. Judy with David Wilding For more photos, and Judy's tweet, click here 28 September 2021 Further introduction of greater water parsnip at Cuttleslowe More young plants grown by Oxford Botanic Garden and Harcourt Arboretum, were brought by Ellie Mayhew, Regional Project Officer, Freshwater Habitats Trust, for introduction to the ponds. As previously, Oxford City Council volunteers prepared the site and helped with planting out. For photos taken by Judy Webb, click here Photo left: Terry Newsome (Oxford City Council volunteer) and Judy Webb doing the planting. Carl Whitehead, coordinator for Oxford City Council volunteers, looking on. |
Burnt Mill Meadow, Oxford August 2021
Photo of greater water parsnip taken by Liz Cooke on 4 August 2021 Full size version here Greater water parsnip is thriving here, helped by a lot of work done by Oxford Conservation Volunteers, Rod D'Ayala and Judy Webb. Clearing of vegetation near the ditch is being carried out to conserve the original population of plants in Burnt Mill meadow. These plants will be augmented by others propagated at Oxford Botanic Garden. Photos of the volunteers at work, and the plant before flowering, on 4 July 2021 are in an album available here |
Milham Ford Nature Park, Oxford
Judy Webb visited the park on 31 July 2021 and subsequently tweeted: 'My flora guardian species greater water parsnip Sium latifolium doing exceptionally well in its introduction site at Milham Ford Nature Park stream, Oxford. @OBGHA* grown plant installed only 1 yr ago in Aug. Now tall with 95 umbels! Fab for #pollinators Typha near needs control.' * Oxford Botanic Garden and Harcourt Arboretum Left: Rod d'Ayala introducing the plant in 2020 To see all Judy's photos, full size, click here |
23 May 2021
Cuttleslowe Meadow
The plants that are visible in this photo are those originally planted.
Within the fencing are some planted later (2021), which were still underwater when the photo was taken.
To see the photo and a close-up, also taken by Judy on 23 May 2021, full size, click here
Information taken from A Guided Walk at Cutteslowe Meadow, filmed at Cutteslowe, 28 July 2020, by The Freshwater Habitats Trust
The photos shown on the right are all taken from that video. Saving Oxford's Wetland Wildlife is a three-year project, currently in its second year, funded primarily by Thames Water, The Trust for Oxfordshire's environment and the Heritage Lottery Fund. It aims to raise awareness of Oxford's freshwater heritage, engage local communities in conserving rare and endangered freshwater wildlife and to look after the city's valuable freshwater sites through practical management work, such as that undertaken at Cutteslowe. Greater water parsnip Sium latifolium is a large umbellifer, standing up to 2m tall. It has declined rapidly over the last 200 years, mainly due to drainage of wetlands and unsuitably managed habitats. It is classified as 'Scarce' in the UK and is a Priority Species for conservation in England and Wales. After propagation at Oxford's Botanic Garden, it was first planted out at Cutteslowe in 2018 in deer-proof cages. The Freshwater Habitats Trust is really grateful for the support of its founders and to its partner organisations, such as Oxford City Council and Oxford Botanic Garden. This collaborative approach to working allows even more to be achieved in helping to safeguard the future of Oxford's wetland wildlife. See the Ex-situ Wetland Plant Project page on the FHT website. Cutteslowe Meadow is a critical area for freshwater biodiversity. It ranks in importance alongside well-known areas such as the New Forest, the Norfolk Broads and the Lake District. However, much of this wildlife is at risk from threats such as climate change, land drainage, pollution and lack of suitable habitat management, and populations are declining. With funding from Thames Water, a contractor and volunteers have been preparing the site for the planting out of some more greater water parsnip plants - part of the collaborative ex-situ wetland plant project run in collaboration with Oxford Botanic Garden and Judy Webb. The Meadow is a complex of seven ponds on the floodplain of the River Cherwell. The site is owned by Oxford City Council and supports important freshwater species including the fast-declining common toad and rare wetland plants, such as tubular water dropwort and greater water parsnip. The original ponds were dug in 2003, funded by The Trust for Oxfordshire's Environment. A number of plants have colonised this site naturally, including lesser spearwort, marsh speedwell and tubular water dropwort, which is a Priority Species in England and Wales. A small temporary pond was overgrown with willows until mid July 2020, when Oxford Conservation Volunteers came to dig them out, enabling low-growing weland plants to thrive. Another, newer, temporary pond is yet to be colonized by wetland vegetation. The Freshwater Habitats Trust will be drawing up a management plan for Cutteslowe in the coming months to ensure that the site and its remarkable freshwater biodiversity continues to be looked after. |
27 August 2020
Introduction of greater water parsnip plants to Cuttleslowe Ponds, Oxford
Judy joined Ellie Mayhew, Regional Project Officer for The Freshwater Habitats Trust, and some Oxford City Council Volunteers led by Carl Whitehead, Coordinator of OCC Volunteers, planting out greater water parsnip plants in ponds caged off to protect them from deer, and clearing unwanted vegetation.
Photos, mostly taken by Judy, are here.
Cutteslowe ponds are part of the Freshwater Habitats Trust's Oxfordshire's Priority Ponds project.
Judy Webb helping with the planting out
On 30 August 2019 Judy tweeted:
'Another of my rare Flora Guardian species, greater water parsnip Sium latifolium doing really well in its trial introduction site in Oxon.
Planted around this pond in a range of water levels. Even seed forming. Thanks to many people!
In 2020 the plan is to remove the cages to see how it survives with deer having access to the plants, but by then it should have dropped seed and we hope to have seedlings.
Great reedmace to be chopped annually near to the cages but not removed'.
Greater Water Parsnip, Sium latifolium
Photo by Judy Webb - more photos by Judy, click here
On 17 August 2017 Judy led an expedition to plant Greater Water Parsnip seedlings at Pinkhill Meadow near Farmoor Reservoir, one of the most species-rich of 70 Flagship Pond Sites the Freshwater Habitats Trust is working to preserve in England and Wales. The Trust had carefully created ideal conditions for the seedlings, which were grown by Oxford University's Botanic Garden from seed collected at another Oxfordshire site
See Oxford Mail article, 23 August 2017.
Below are Judy's reports on Sium latifolium published in the annual newsletters of the
Oxfordshire Flora Group of the Ashmoleum Natural History Society of Oxford
Oxfordshire Flora Group of the Ashmoleum Natural History Society of Oxford
Newsletter 2018 p. 16 (no Newsletter in 2017)
2018 has been a difficult year for this tall wetland perennial umbellifer, which is on the GB Red List, is on the England Red List as Endangered and is also a Section 41 (UK BAP Priority species). It requires sites that ideally remain with water around the plant roots for most of the year and it does not like to grow in water greater than 40cm deep or where the water table drops below 30cm of soil surface.
The largest population on the margins at Hagley Pool ditch near Wytham in the SSSI was fine as water levels remained high in the wide ditch throughout the summer heat and drought. The number of clumps remains down at three, with the loss of the gate clump that has not been seen for two years in succession (perhaps due to elimination by competition from reed) but there was evidence of young plants surviving near the main clumps (previous efforts at introducing propagated plants from Wytham seed). Good flowering was followed by good seed set and Jim Penny of Oxford Botanic Garden (OBG) and I were able to collect a large quantity of seed in early October. The garden staff will propagate from this seed and grow on plants for augmentation of the Wytham population and for introduction to new suitable sites.
Elsewhere, the small population on the edge of a ditch in Burnt Mill meadow near the Cherwell in Marston did very poorly. The meadow and the ditch dried out completely in the hot and dry summer. Well-grown mature Sium plants produced a number of flowering stems and inflorescences, but these shrivelled and no seed was set. In the introduction site of a pond at Milham Ford Nature Park, it was a similar story. The pond dried right down to mud in the summer heat and drought and the solitary mature plant flowered but formed no seed. The 15 or so young plants that had naturally germinated from dropped seed in previous years were on a now high and dry on the bank margin, where they were struggling against rank vegetation. The decision was made to remove these young plants and take them into protective care in pots in a garden. Here they could be grown on to a larger size and perhaps planted out further near the centre of the pond where conditions may remain wetter during future summers. It may be the case, however, with accelerating climate change meaning frequent hot and dry summers, neither Burnt Mill meadow ditch or Milham Ford Nature Park pond will be suitable for this species in future years and a deal of thought is being given to finding a
new wetter home for both populations.
With this in mind, a trial introduction to a pond in Cutteslowe Park was carried out in August 2018. This pond is in the floodplain of the Cherwell river. OBG staff supplied some well grown propagated Sium plants, Oxford City Council Countryside Service volunteers prepared the pond site and volunteers from the Environment Agency and the Freshwater Habitats Trust pulled up greater reed mace in two areas of one pond and planted out eight Sium in a range of hydrologies, from the margin of the pond to the centre. The planted areas were enclosed in a fence to deter deer from eating the young plants. The winter rains have filled the pond and the emergence and success of the Sium plantings will be carefully monitored next year.
This photograph, taken by Judy Webb on 21 August, shows the planting out in the deer-proof cage at Cutteslowe Park
2018 has been a difficult year for this tall wetland perennial umbellifer, which is on the GB Red List, is on the England Red List as Endangered and is also a Section 41 (UK BAP Priority species). It requires sites that ideally remain with water around the plant roots for most of the year and it does not like to grow in water greater than 40cm deep or where the water table drops below 30cm of soil surface.
The largest population on the margins at Hagley Pool ditch near Wytham in the SSSI was fine as water levels remained high in the wide ditch throughout the summer heat and drought. The number of clumps remains down at three, with the loss of the gate clump that has not been seen for two years in succession (perhaps due to elimination by competition from reed) but there was evidence of young plants surviving near the main clumps (previous efforts at introducing propagated plants from Wytham seed). Good flowering was followed by good seed set and Jim Penny of Oxford Botanic Garden (OBG) and I were able to collect a large quantity of seed in early October. The garden staff will propagate from this seed and grow on plants for augmentation of the Wytham population and for introduction to new suitable sites.
Elsewhere, the small population on the edge of a ditch in Burnt Mill meadow near the Cherwell in Marston did very poorly. The meadow and the ditch dried out completely in the hot and dry summer. Well-grown mature Sium plants produced a number of flowering stems and inflorescences, but these shrivelled and no seed was set. In the introduction site of a pond at Milham Ford Nature Park, it was a similar story. The pond dried right down to mud in the summer heat and drought and the solitary mature plant flowered but formed no seed. The 15 or so young plants that had naturally germinated from dropped seed in previous years were on a now high and dry on the bank margin, where they were struggling against rank vegetation. The decision was made to remove these young plants and take them into protective care in pots in a garden. Here they could be grown on to a larger size and perhaps planted out further near the centre of the pond where conditions may remain wetter during future summers. It may be the case, however, with accelerating climate change meaning frequent hot and dry summers, neither Burnt Mill meadow ditch or Milham Ford Nature Park pond will be suitable for this species in future years and a deal of thought is being given to finding a
new wetter home for both populations.
With this in mind, a trial introduction to a pond in Cutteslowe Park was carried out in August 2018. This pond is in the floodplain of the Cherwell river. OBG staff supplied some well grown propagated Sium plants, Oxford City Council Countryside Service volunteers prepared the pond site and volunteers from the Environment Agency and the Freshwater Habitats Trust pulled up greater reed mace in two areas of one pond and planted out eight Sium in a range of hydrologies, from the margin of the pond to the centre. The planted areas were enclosed in a fence to deter deer from eating the young plants. The winter rains have filled the pond and the emergence and success of the Sium plantings will be carefully monitored next year.
This photograph, taken by Judy Webb on 21 August, shows the planting out in the deer-proof cage at Cutteslowe Park
Newsletter 2016, pp 12-13 (no Newsletter in 2017)
The small Marston Meadows population of Sium latifolium had its worst year since monitoring started, with all three mature plants that should have flowered, eaten to the ground by deer. There was, therefore, no 13 chance of seed production. Shearing back the dense Lesser Pond-sedge Carex acutiformis next to the mature plants revealed a small number of young Sium plants and some seedlings, however.
There is a reserve population grown from Marston Meadows seed and maintained in Milham Ford Nature Park in the shallow margin of one pond. In summer 2016 two mature plants of Sium were present and flowered, but subsequently no seed was set when checked in late September. A search of the marginal wet vegetation revealed a number of young Sium plants and the competing vegetation was sheared back to enable them to have a better chance of growing well and flowering next year.
The small Marston Meadows population of Sium latifolium had its worst year since monitoring started, with all three mature plants that should have flowered, eaten to the ground by deer. There was, therefore, no 13 chance of seed production. Shearing back the dense Lesser Pond-sedge Carex acutiformis next to the mature plants revealed a small number of young Sium plants and some seedlings, however.
There is a reserve population grown from Marston Meadows seed and maintained in Milham Ford Nature Park in the shallow margin of one pond. In summer 2016 two mature plants of Sium were present and flowered, but subsequently no seed was set when checked in late September. A search of the marginal wet vegetation revealed a number of young Sium plants and the competing vegetation was sheared back to enable them to have a better chance of growing well and flowering next year.
1 August 2015 Judy led a survey of the plant's populations in Old Marston
See Oxford Mail article, 5 August 2015, on Oxfordshire's 'Flora Guardians', which also refers to Creeping Marshwort
See Oxford Mail article, 5 August 2015, on Oxfordshire's 'Flora Guardians', which also refers to Creeping Marshwort
From 'Greater Water Parsnip Replanted', Oxford Botanic Garden and Harcourt Arboretum blogspot, 8 October 2014 :
'The greater water parsnip, Sium latifolium, is a plant of fens and wet ditches which grows in still or slow-moving water, sometimes emerging from rafts of floating vegetation. It grows to 2m in height, producing large umbels of white flowers in mid to late summer. Despite being related to the culinary parsnip, it is, like many other umbellifers, poisonous. Restricted to floodplains and fens to the east and south of England, the population of this plant has suffered a sharp decline in the last 40 years, mainly due to the destruction of its habitat through drainage, land reclamation and changes in the way water levels are managed. It may also be affected by high levels of nutrients in water caused by fertiliser run-off. Now categorised by the IUCN as Endangered, Sium latifolium is also a priority species for the UK Biodiversity Action Plan.
In Oxfordshire, the Oxfordshire Flora Group is actively involved in the conservation of this species (among many others). Last year, [2013] the Botanic Garden raised plants from seed collected in an SSSI near Wytham, to provide the Group with plants to reintroduce at the same site, helping to boost the population".
From 'Greater Water Parsnip Replanted', Oxford Botanic Garden and Harcourt Arboretum blogspot, 8 October 2014 :
'The greater water parsnip, Sium latifolium, is a plant of fens and wet ditches which grows in still or slow-moving water, sometimes emerging from rafts of floating vegetation. It grows to 2m in height, producing large umbels of white flowers in mid to late summer. Despite being related to the culinary parsnip, it is, like many other umbellifers, poisonous. Restricted to floodplains and fens to the east and south of England, the population of this plant has suffered a sharp decline in the last 40 years, mainly due to the destruction of its habitat through drainage, land reclamation and changes in the way water levels are managed. It may also be affected by high levels of nutrients in water caused by fertiliser run-off. Now categorised by the IUCN as Endangered, Sium latifolium is also a priority species for the UK Biodiversity Action Plan.
In Oxfordshire, the Oxfordshire Flora Group is actively involved in the conservation of this species (among many others). Last year, [2013] the Botanic Garden raised plants from seed collected in an SSSI near Wytham, to provide the Group with plants to reintroduce at the same site, helping to boost the population".