Narrow-leaved water-dropwort, Oenanthe silaifolia
Photo by Judy Webb
Near Threatened on the GB Red List and scarce in Oxfordshire, this plant is found in damp grassland that receives calcareous flood-water in winter.
Information from the ANHSO Oxfordshire Flora Group
Judy's reports for the Group's annual newsletter:
2018 page 11 2019 page 13 2020 page 8 (No report in 2021) 2022 page 13
Photo by Judy Webb
Near Threatened on the GB Red List and scarce in Oxfordshire, this plant is found in damp grassland that receives calcareous flood-water in winter.
Information from the ANHSO Oxfordshire Flora Group
Judy's reports for the Group's annual newsletter:
2018 page 11 2019 page 13 2020 page 8 (No report in 2021) 2022 page 13
12 June 2021
David Morris, the BSBI vascular plant recorder for the vice-county of Oxfordshire (V.C. 23), and Judy Webb carried out a survey of an MG4 old ridge-and-furrow meadow LWS (Local Wildlife Site) in Oxfordshire. To Judy's delight, 166 flowering plants of narrow-leaved water-dropwort were among the species found. To see photos and comments tweeted by Judy and David, click here
David Morris, the BSBI vascular plant recorder for the vice-county of Oxfordshire (V.C. 23), and Judy Webb carried out a survey of an MG4 old ridge-and-furrow meadow LWS (Local Wildlife Site) in Oxfordshire. To Judy's delight, 166 flowering plants of narrow-leaved water-dropwort were among the species found. To see photos and comments tweeted by Judy and David, click here
Hyperlinks given in the extracts from Judy's reports below have been added to the original versions
Oenanthe silaifolia - photo by Judy Webb, 10 May 2019
Judy's report published in the Oxfordshire Flora Group's Newsletter 2019, p. 13
'This species is Near Threatened on the GB Red List, scarce in Oxon. It particularly likes wetter versions (or wetter areas) of floodplain meadows. Oenanthe silaifolia has six current sites in the county.
I regularly visit the small population in Yarnton West Mead (part of Oxford Meadows SAC, floodplain of the Thames), where it lives in shallow grassy and sedgey palaeochannels. Here at my visit on 10 May it was seen to be suffering much from the drought, with browning leaves and inflorescences. If climate change brings regular dry warm springs with a low water table, it will probably mean this site becomes unsuitable for this plant in the future'.
Photo of Oenanthe silaifolia taken by Judy Webb, 15 06 2018
Judy's report published in the Oxfordshire Flora Group's Newsletter 2018, p. 11
'This species is Near Threatened on the GB Red List, scarce in Oxfordshire and particularly likes wetter versions (or wetter areas) of floodplain meadows. Up until this year, this species had 5 post-2000 known sites in the county. I regularly visit the small population in Yarnton West Mead (part of Oxford Meadows SAC, floodplain of Thames) but its two strongholds with large populations appear to be Bestmoor SSSI and Meadow Farm Meadows LWS, owned by BBOWT adjacent to the river Ray'.
There are other concentrations of this plant in meadows adjacent to the Ray, such as Arncott Bridge Meadows SSSI and in non-SSSI meadows nearby. David Morris found small amounts in new sites this year in four positions in meadows next to the River Ray in the Arncott area and near Ambrosden and one at Astley Bridge. Tanya Smith, whilst surveying the wetter type of floodplain meadows for her MSc thesis, discovered a new large population near
Souldern, north-west of Bicester in the floodplain of the Cherwell. This is the largest population I have seen
and she is to be congratulated on this important discovery.
All populations seem to be secure currently and not under threat of any change in management.'
Judy's report published in the Oxfordshire Flora Group's Newsletter 2018, p. 11
'This species is Near Threatened on the GB Red List, scarce in Oxfordshire and particularly likes wetter versions (or wetter areas) of floodplain meadows. Up until this year, this species had 5 post-2000 known sites in the county. I regularly visit the small population in Yarnton West Mead (part of Oxford Meadows SAC, floodplain of Thames) but its two strongholds with large populations appear to be Bestmoor SSSI and Meadow Farm Meadows LWS, owned by BBOWT adjacent to the river Ray'.
There are other concentrations of this plant in meadows adjacent to the Ray, such as Arncott Bridge Meadows SSSI and in non-SSSI meadows nearby. David Morris found small amounts in new sites this year in four positions in meadows next to the River Ray in the Arncott area and near Ambrosden and one at Astley Bridge. Tanya Smith, whilst surveying the wetter type of floodplain meadows for her MSc thesis, discovered a new large population near
Souldern, north-west of Bicester in the floodplain of the Cherwell. This is the largest population I have seen
and she is to be congratulated on this important discovery.
All populations seem to be secure currently and not under threat of any change in management.'
Maturing seeds of Narrow-leaved Water-dropwort, Yarnton West Mead - photo by Judy Webb
Judy's report published in the Oxfordshire Flora Group's Newsletter 2016, p. 9
(no report for 2017)
'A planned visit to the population in Arncott Bridge Meadows could, in the end, not happen at peak flowering time. Instead I decided to look at fruiting success in the nearest population in Yarnton West Mead, part of Oxford Meadows SAC, where Oenanthe silaifolia is present in the wetter soil of the palaeochannel areas.
A visit on 14 July 2016, which was estimated to be just prior to the hay cut, revealed a good number of plants with maturing green to orange red-flushed seed, but this was obviously still immature and tightly fixed, thus not yet ready for dispersal. Unless the seeds were able to mature in the cut hay, it seems very likely that seed would not have dropped to the ground but been taken away off site in the hay in an immature state. This is obviously a species that only returns a good number of mature viable seeds to the soil in a year when the hay cut is very late, giving time for seed maturation. As it is a long-lived perennial, this may not be a problem for long term population health.'
Judy's report published in the Oxfordshire Flora Group's Newsletter 2016, p. 9
(no report for 2017)
'A planned visit to the population in Arncott Bridge Meadows could, in the end, not happen at peak flowering time. Instead I decided to look at fruiting success in the nearest population in Yarnton West Mead, part of Oxford Meadows SAC, where Oenanthe silaifolia is present in the wetter soil of the palaeochannel areas.
A visit on 14 July 2016, which was estimated to be just prior to the hay cut, revealed a good number of plants with maturing green to orange red-flushed seed, but this was obviously still immature and tightly fixed, thus not yet ready for dispersal. Unless the seeds were able to mature in the cut hay, it seems very likely that seed would not have dropped to the ground but been taken away off site in the hay in an immature state. This is obviously a species that only returns a good number of mature viable seeds to the soil in a year when the hay cut is very late, giving time for seed maturation. As it is a long-lived perennial, this may not be a problem for long term population health.'