Through the summer and autumn of 2010, Louise Hill and other members of the Doncaster Naturalists’ Society have been monitoring the progress of the newly arrived and highly invasive American Floating Pennywort Hydrocotyle ranunculoides in the River Don and South Yorkshire Navigation in the Doncaster region. Substantial populations are currently present at Sprotbrough Locks, the course of the old River Cheswold at Crimpsall and in the Canal basin opposite St George’s Minster in central Doncaster (see Figure below). Smaller populations have been noted on the Don at Sprotbrough Falls, Church Rein, Hexthorpe (opposite the allotment dog-leg), Crimpsall Rock Chute and in the canal at Strawberry Island and Long Sandall.
In addition to these sites, Geoffrey Wilmore (YNU Alien Plants recorder) knew of the plant in South Yorkshire back in 2000 when Jeff Lunn reported it the Barnsley Canal at Wilthorpe. In West Yorkshire Geoffrey Wilmore and Jill Lucas monitored its appearance in a small brook in Huddersfield in 2005, and its colonisation of the Calder and Hebble Navigation notably the ‘Figure of Three’ Locks at Horbury and riverside flashes in the Ossett and Horbury areas.
During 2010 the Environment Agency has employed a contractor to spray with herbicide any Floating Pennywort colonies found from the Rother all the way down the Don and South Yorkshire Navigation to Crimpsall (Doncaster prison) (twice). Over the next few weeks the EA is also surveying the Rother (by canoe!) all the way up to Chesterfield to try to find the source of the infestation. In addition, the EA is also dealing with it on the Aire and Calder Navigation at Castleford.
The Environment Agency with various partner organisations including British Waterways, Doncaster and Wakefield Councils and the Don Rivers Trust and the Colne & Calder Rivers Trust has formed the ‘Yorkshire Pennywort Forum’. Its aims are to provide a co-ordinated response to this invasive weed, to record and monitor its spread in Yorkshire and to tackle it in key areas.
In 2010 British Waterways allocated £20K for Pennywort control, and a further £10K is coming from the Flood Risk Management team at the Environment Agency. As a result in 2010 it has targeted pennywort control on the Rivers Don, Rother and Calder.
A useful website on American Floating Pennywort in the UK is:
Louise Hill & Colin Howes (Doncaster Naturalists’ Society)
Harry Woolner from Buglife introduced the Urban Buzz project to Yorkshire Naturalists' Union members at the YNU's Natural Sciences Forum meeting on the 14th November.
Urban Buzz is a new national project run by Buglife and funded primarily by Biffa Award with the aim of increasing pollinator habitat in cities. It has two key aims: to engage and train volunteers in habitat creation and enhancement, site assessment and monitoring, and to improve sites for the benefit of pollinators, aiming for 100 sites, large and small, across York.
The project will run for 18 months in York but the aim is to set up a legacy of ongoing monitoring.
Urban Buzz York would like input from the YNU on:
- Suggestions for potential sites, i.e. areas where habitat enhancement could be particularly beneficial and/or there is already an active group of volunteers.
- Offers to support the project in any way, e.g. habitat creation, site assessment or monitoring, training and mentoring volunteers.
Photograph by Barry Warrington.
On 20 September 2009, during a visit to the gardens at Brodsworth Park, an English Heritage property, situated on the Magnesian limestone ridge northwest of Doncaster (SE/5007), Colin Howes and Elizabeth Farningham of the Doncaster Naturalists’ Society encountered a single plant of a wild Dianthus species. A photograph of a single flower taken by Pip Seccombe was subsequently confirmed by Geoffrey Wilmore as Dianthus deltoides (Maiden Pink).
Although the plant in question appeared to be growing opportunistically in a scuffed gully (see photograph 2) on a steep bank bordering the steep (15%) path leading up from the rose pergola, it could have been introduced as part of the Victorian garden restoration
The site was visited again on 13 June 2010 and although additional clumps were located adjacent to the original patch, the ground flora of the bank, which included Common Ivy (Hedera helix), Periwinkle (Vinca sp.), Wild Strawberry (Potentilla vesca), Columbine (Aquilegia vulgaris) (seedlings) and Violet (Viola sp.) had been strimmed so no flowers or buds were present.
A visit on 31 August 2010 successfully located some 11 discrete patches of the plant along a 12 meter stretch of the same bank. Again the ground-cover vegetation had been strimmed but a few late season flowers were present (see photograph 3). On this occasion two English Heritage gardeners working near by were asked about the plant but were not aware of it’s presence or whether it had been introduced. However in the new rockery at the far side of the gardens, a miniature Dianthus had been planted but this was the ornately flowered Fringed Pink (D. monspessulanus sternbergii).
In the context of South Yorkshire there were just two 19th century records of Dianthus deltoides (Maiden Pink), these from the lawns of Cantley Vicarage (SE/6101) in 1844-46 and from a gravely bank near the now defunct Sprotbrough Railway Station (SE/5301) in 1881. In the 1980s there was an ephemeral occurrence in limestone rubble near Thorne colliery (SE/7016).
In a wider Yorkshire context, the floras of North, East and West Yorkshire refer to very few records, most of which relate to the 19th of early 20th centuries.
The New Atlas of the British and Irish Flora (2002) only lists occurrences in 88 10km squares for the whole of Britain and Ireland, down from 144 in 1970 and The Vascular Plant Red Data List for Great Britain (2005) list it as 'Near Threatened'.