The Whitty Pear - Sorbus domestica L. A Natural Pioneer Millennium Award Project, Work in Progress

By Frances Claxton


In January 1999 I rang Will Watson and asked him if there were any 'juicy' locally distinctive tree species. In his answer he included Sorbus domestica, also known as the Whitty Pear, the Sorb Tree or the True Service tree. I had grown up in Worcestershire and had just returned from Northern Ireland where I had developed a passion for scarce native tree species. In May, I was awarded a Natural Pioneer Millennium Award that would pay for my training to equip me to deliver a project working towards the local Species Action Plan for Sorbus domestica.1 The project is now at its half-way stage and Harry Green has asked me to write this report. I will attempt to discuss what the project has involved and place it in the local and national context.

The importance of S.domestica is clear from European to local level. Europe-wide S.domestica is recognised as needing action in the EU GENRES programme2. It is the most endangered tree species in Switzerland with 300 individuals, which contrasts with 23 wild individuals plus 22 suckers that have been found in the UK3. In the UK, the species is classed as 'critically endangered'4. English Nature has chosen S.domestica as the only tree species to have a current 'Species Recovery Plan'. The Royal Botanic Gardens, Kew who chose S.domestica to be one of its 'Threatened Plant Appeals' species has found that it has stimulated a greater response than any other current TPA species, including tropical species. Locally, there is an individual Species Action Plan for the True Service Tree within the Worcestershire Biodiversity Action Plan.

Eleven tree species in Britain are in danger of extinction - all of which are members of the Sorbus genus5. It was the opinion of Sorbus experts who participated in a workshop held at Wakehurst Place in April of 1996, that Sorbus domestica shared joint top priority in terms of conservation in the UK, with S.bristoliensis, S.leyana and S.wilmottiana6. Others would go further and point out that, since S.domestica is in a subgenus of its own, subgenus Cormus, and it is the only sexual species of the four, that S.domestica could be considered priority number one in terms of conservation of tree species in the UK.

A brief history

The first individual of Sorbus domestica recorded in the UK was reported from the Wyre Forest in 1677 by Alderman Edmund Pitt of Worcester. In the 1800's a poacher burnt the tree down and some say was transported to Australia for his crimes! Luckily some cuttings had been taken and propagated at nearby Arley Castle in the early 1800's. The memory of the tree remained close to the communities' heart and one of the Arley saplings was planted back into the Wyre forest on 30th March 1916 on the site of the original tree in memory of Robert Woodward, son of the Arley Castle Family, who was killed in the war. Many descendants of the Arley saplings are still growing throughout the county, including those in Bewdley, College Green and the Bishop's Palace gardens, Worcester. There are also many more planted individuals whose origin is unknown. Despite there being historical references in Welsh poetry dating back to the 9th century, the Wyre individuals were for a long time thought to be the only known living trees which might still hold the genes of native S.domestica in the Britain. (Note: The history of the Sorb Tree in Worcestershire is told by Mary Munslow Jones in her book The Lookers-out of Worcestershire 1980, and there are many references to the tree in the Transaction of the Worcestershire Naturalists Club. A bibliography of the species is being prepare by the Sotbus domestica Study Group)

In 1983 a population was found by Marc Hampton on a South facing Lias limestone seacliff in Glamorgan. An individual in this population has been estimated to be c.400 years old!7 Since then a second site has been found in Glamorgan and three sites had been discovered in Gloucestershire8. In August 1999 while Mark and Clare Kitchen were showing me the Gloucestershire sites Mark Kitchen discovered another individual. The new tree is sufficient distance away from another site on the River Severn to be considered a separate population.

Project objectives and progress (See Table 1)

Table 1: Summary of contribution made towards species Action Plan objectives, May-October 1999

SAP objectives (summary)
Natural pioneer Project contributionSurveying for new records of wild S.domesica plants in prioritised areas. Recommended time: Flowering in May or fruiting seasons in September/October.


2 days surveying some potential sites in the Teme Valley and along the River Severn with local Tree Warden Roger Claxton.
No S.domestica sites found however some findings noted.

Establish database of known trees. Information to be transfered to GIS when available. Database established with help from Worcestershire Sorb dom group members. Used to date during leaf sample collecting and analysis of molecular results at Kew.
Molecular research Leaf samples collected from 24 Worcestershire trees and 2 Gloucestershire sites with local involvement. These were added to samples from throughout Europe. See List 1.
Four weeks work experience completed in the Conservation Genetics Unit at Kew under the supervision of Robyn Cowan. I am continuing to do research there on a voluntary part-time basis. Report of findings expected Spring 2000.
Profile raising
Gather and collate information and distribute
Publicise the history and importance of the species
Educational materials about biodiversity conservation being prepared. These will include four case studies, the main one being about Sorbus domestica. This work is being done in partnership with:
Natural History Museum, London
Henry Doubleday Research Association, Coventry
Royal Botanic Gardens, Kew
Professional Seed Collectors in Scotland.
Bishopswood Environment Centre
2 out of 5 educational events booked for Spring 2000
Propagation Two collections of seed made for Kew UK Millennium Seed Bank Project from:
  1. Pyriform individual, Suffolk, by Waverney District Council.
  2. Maliform individual, Worcestershire.
*Attempts made to collect wild seed from Gloucestershire were unsuccessful.

Surveying in Worcestershire

I undertook two short spring searches for Sorbus domestica trees in Worcestershire without success..

Day 1:

Titton barracks near Lincomb (Grid Ref: SO820690) to the Hollies woodland down stream along the River Severn. Between SO820690 and river bank the following tree and shrub species were noted in the natural woodland: Tilia cordata and Tilia platyphyllos, Crataegus monogyna, Quercus, Prunus avium, Corylus avellena, Acer campestre, Fraxinus excelsior, Ilex aquifolium, Ulmus, Cornus sanguinea.

Moving down stream to Winnall coppice naturally wooded slope with marsh at base of slope and then woodland at the Hollies we saw the same tree species composition occurred at both sites. All three woodlands are on sandstone with unstable soil surfaces.

Day 2:

Homme Castle near Clifton-Upon-Teme north to Shelsley Walsh. Weyman's Wood towards Top Barn (SO621724). Veteran Taxus baccata, abundant Sorbus torminalis including good natural regeneration, and Tilia cordata. We attempted to locate the limestone seam seen on geology maps meandering along the contours in this area. We assumed that any S.domestica might be growing near this seam. The mature Yews were consistently on one contour so we followed them. We continued down Witchery Hole, skirted round ascending steeply out of the quagmire to Rock Wood. At SO623723 there are extensive active badger sets. We descended to Shelsley Walsh.

Two miles north of Homme Castle, just north of Furnace Farm, surveying South to the Shelsley Walsh.
We surveyed Rock Coppice round to the top of Devil's Den and Hell Hole. Along this stretch there are some veteran Yews of an impressive girth on the slope. Finally we descended returning to Shelsley Walsh.


Fraxinus excelsior was an abundant species throughout both days surveying. With hindsight it would be much more efficient to survey for S.domestica while its leaves are exhibiting their autumn colour (September-October), rather than when they are blooming in May. S. domestica inflorescences are inconspicuous from a distance, while their autumn colour includes vibrant reds and oranges that would help distinguish it from both S.aucuparia and young F.excelsior individuals from a distance. It may also be useful to know when F.excelsior drops its leaves in relation to S.domestica, despite this being effected by many other factors.

Figure 1 The original Whitty Pear (Nash 1799)

Since visiting all six suspected wild sites known of in the UK, I am now certain that there are more unrecorded S.domestica individuals, perhaps even in Worcestershire! In brief, the reasoning behind my optimism is based on the characteristics of the Gloucestershire sites. The Glamorgan sites have individuals suckering for up to 200m stretches of South facing exposed Lias limestone seacliffs, undercut by salt marsh. The individuals seemed to be repelled by encroaching woodland on less sheer gradients and on both sites there was Maiden Hair Fern Adiantum capillus veneris, Purple Gromwell Lithospernum purpureocaeruleum and a Fleabane Inula. Combined, these site characteristics are very specific. Many sites that share these characteristics in the UK, have already been identified, and have been relatively easy to survey with binoculars.9 In contrast, sites in Gloucestershire have many characteristics that are found frequently in Worcestershire and elsewhere. For example, the geology has Lias limestone as a small component of the slope profile, the rest of the slope is comprised primarily of sandstone. The slopes are densely wooded, sheer, unstable and in most cases can not be viewed from the top of the slope. These qualities make them very difficult to actively survey either close up or with binoculars. I feel the only safe way that botanists could be certain about an 10area of slope would be to carry out transacts at regular intervals on ropes from the top of the slope. However, it is more likely that sites will continue to be discovered by seeing new windows into the wooded slopes due to land slippage, which is how new site was discovered in August of this year. The species that are consistently associated with S.domestica in Gloucestershire are S. torminalis and wild madder Rubia peregrina.[latter does not occur in Worcestershire] .I would be interested to see the results of a coincidence search of sites in Worcestershire, or elsewhere, which share the Gloucestershire geological and botanical characteristics. This would be very useful information on which to base further surveying.

Molecular research

The molecular research being conducted at Kew uses the AFLP Plant Mapping technique11. AFLP is particularly well suited to assessing the degree of genetic variability within a species and the degree of relatedness between individuals within a species. In Worcestershire there is one burning question on everyone's lips - How does the Whitty Pear that grew in the Wyre Forest relate to those recently found in Gloucestershire and Glamorgan? The research is attempting to address this question amongst others.

With the help of local enthusiasts I collected leaf samples from 28 S. domestica individuals. (A note for future samplers: using polepruners would have been a really good idea!) All these samples were from Worcestershire with the exception of two from Gloucestershire. Up to five grams of fully formed leaf material was collected from each tree, torn into small pieces and added immediately to a 50g bag of fine grain silica gel. The silica gel removes moisture from the leaves, indicated by a colour change in a gel. . It is important that leaf material is dried within 24 hours of collection to avoid DNA degradation. Therefore the silica must not be overloaded. It was also important to avoid leaves with rust where possible. A herbarium sheet of the material serves as the voucher for the DNA of each sample and these are best pressed between paper in the field. In addition, Pam Thaw arranged for the collection of the Taunton sample, Harry Green collected the Italian (Umbria) sample and Jon Stokes of the Tree Warden Scheme/Tree Council collected the Suffolk sample.

These 28 samples were added to others from England, Wales and from throughout Europe, totalling 74 samples from eight countries, (see Table 2). Currently, DNA of 71 samples has been totally extracted. All totally extracted DNA from this research is stored in Kew's DNA bank available for use in this and future research involving Sorbus domestica. The three remaining samples are late comers and are half way through extraction. Every sample goes through the AFLP and electrophoresis process in triplicate. This is because a different genetic 'primer' or label is attached to each one of these, to obtain different information about the sample. Forty-five samples have already gone through the AFLP process and electrophoresis, and the data is being edited on the Genotype™ computer program. The remaining 29 samples plus a number of repeats will also go through this process. Once all the data is collated and edited, the three sets of information will be combined for each sample, then phylogenetic analysis of the data will begin. I am very lucky that Kew have given me the opportunity to write the report with them for English Nature. I am unable to realistically predict the timing of the final report as this is the first time I have carried out this process. However one snippet of information based on the information from one primer suggests that the Croome Perry Wood tree and the Oxford Botanic Garden maliform specimen are genetically indistinguishable using this technique. This suggests that they could have been vegetatively reproduced from the same origin.

List 1: Sites of samples included in the current molecular research at Kew, part of the work for English Nature's Species recovery plan for Sorbus domestica.

Site NameCountry
K08 Progeny 7Austria
Bergenland 1Austria
K09 AdultAustria
K08 AdultAustria
Bergenland 3Austria
K09 Progeny 1Austria
Bergenland 4Austria
Bergenland 5Austria
K08 Progeny 1Austria
K08 Progeny 2Austria
K08 Progeny 3Austria
K08 Progeny 4Austria
Bergenland 2Austria
K08 Progeny 6Austria
K09 Progeny 2Austria
K09 Progeny 3Austria
K09 Progeny 4Austria
K09 Progeny 5Austria
K09 Progeny 6Austria
K09 Progeny 7Austria
K09 Progeny 8Austria
K09 Progeny 9Austria
K09 Progeny 10Austria
K08 Progeny 8Austria
K08 Progeny 9Austria
K08 Progeny 10Austria
K08 Progeny 5Austria
Loen, Callow Hill, Bewdley. England
Croome Perry WoodEngland
Croome CourtEngland
Oxford Botanic Garden - PyriformEngland
Arley Arboretum - Main gate 1England
Forestry House No.19England
Wyre Forest Visitor CentreEngland
Withybed Wood 5 - Cadbury ForestEngland
Withybed Wood 4 - Cadbury ForestEngland
Withybed Wood 3 - Cadbury ForestEngland
Withybed Wood 2 - Cadbury ForestEngland
Withybed Wood 1, Cadbury ForestEngland
Wyre Forest 4England
Wyre Forest - Site no. 57England
Cubsmore field treeEngland
Cadbury Forest -Woodland Chalet 3England
Suffolk treeEngland
Croome Perry Wood ,second treeEngland
Arley Arboretum Main Arboretum second tree (Cat 68). England
Arley Arboretum - Cat. No. 74England
Arley Arboretum - Main gate 4England
Shirehampton, GloucestershireEngland
Arley Arboretum - Main gate 2England
Cadbury Forest -Woodland Chalet 2England
Cadbury Forest - Woodland Chalet 1England
Taunton treeEngland
Gatcombe, Gloucestershire. England
Sedbury, Gloucester. England
Arley Arboretum - Main gate 3England
Wyre Forest 1 - 90 year oldEngland
Poole House, Astley Town, StourportEngland
Oxford Botanic Garden - MaliformEngland
College Green, Worcester CathedralEngland
Bishop's Palace Garden, WorcesterEngland
Maquis vegetation, Aude Herault. France
Thenon, Auxerre. France
Quercus pubescens woodland, Dordogne. France
Rochusbery, BirgenGermany
Umbria. Italy
Northern PyrinesSpain
Geneva Botanic Garden (Wild plant) Switzerland
Bois de Chatillion, GenevaSwitzerland
Quercetalia-Pubescenti, GenevaSwitzerland
Chateau de Penthes, Pregny. Switzerland
Porthkerry, Sample from West end of population. Wales
Porthkerry, Sample from East end of population. Wales
Fontygary, Aberthaw, Vale of Glamorgan. Wales
This information is taken from the S. domestica database.


The training I have received from this Millennium Award and local experts has enabled me to deliver this project to date. This is something I am very grateful for. As for Sorbus domestica, with discoveries of new information like 'Der Speierling'12 a German book documenting how the species is currently involved in industry and as part of German culture, the species becomes even more interesting. It is a shame that S. domestica is not the most aesthetic tree in the UK, due to it being on the extreme of its natural geographical range. It is obvious to me that this species is so rich in cultural history that it has great amenity value. It seems very sad that at present there is an unwillingness to recognise their value by protecting planted individuals with Tree Preservation Orders.

As for the wild populations, I hope the molecular work, which is one of the starting points of the English Nature Species Recovery Plan, will be the first step towards the active conservation of this amazing survivor in the UK.


Natural Pioneer Millennium Awards Unit, BTCV, Wallingford. Members of the Worcester Sorbus domestica group, especially: Harry Green, Fred Jennings, John Bulmer, John Hodson, Rosemary Winnal and Will Watson. Mark Hampton, Glamorgan; Fiona Copper, Shropshire; and Mark and Clare Kitchen, Gloucestershire The Royal Botanic Gardens Kew, in particular Dr Mike Fay and Robyn Cowan from Conservation Genetics, and Andrew Jackson, Bill Baker and Hugh Prendergast. Jon Cree and John Rymer from the Bishops Wood Centre, Stourport-on-Severn. Simon Pratt, Redfield Community, near Aylesbury. Jon Stokes, Tree Council; and Dr Quentin Kay. Dr Anthony Coles from Worcester College of Technology. Karen Sidwell, Natural History Museum, London; and Louise Daugherty, the Henry Doubleday Research Association.
Natural Pioneer Award is a training grant, funded by the Millennium Commission and administered by BTCV throughout the UK.
Frances Claxton can be contacted at


HAMPTON M 1996 Sorbus domestica L. Comparative Morphology and Habitats. BSBI News No 73 p32-37
HAMPTON M & KAY QON 1995 Sorbus domestica L new to Wales and the British Isles. Watsonia 20:379-384
JEFFERY FR 1916 The Wyre Forest Sorb Tree Worcestershire Naturalists' Club Transactions Vol VI part III pages 250-257
JONES, MARY MUNSLOW 1980 The Lookers-out of Worcestershire. The Worcestershire Naturalists' Club.
MARREN, PETER 1999 Britain's Rare Flowers. Poyser Natural History


  1. The local Biodiversity Action Plan is available form at the Worcester Wildlife Trust.
  2. EU GENRES programme is the European programme on characterisation, collection and utilisation of genetic resources in agriculture. S. domestica is in project 29.
  3. Taken from 'The Conservation Status of Sorbus in the UK with the addition of the August 1999 site. See footnote no. 8.
  4. From the Red Data Book of rare plant species, under the Joint Nature Conservation Committee.
  5. A fact reported by the World Conservation Monitoring Centre and the World Conservation Union, 1998. 'Tree News', Autumn 1998.
  6. Taken from 'The Conservation Status of Sorbus in the UK proceedings of the Workshop held at Wakehurst Place 28th April 1996', edited by Andy Jackson and Mark Flanagan from Royal Botanic Gardens Kew, Wakehurst Place. Published by Kew February 1998.
  7. 'Sorbus domestica L., new to Wales and the British Isles', by M. Hampton and Dr Q. O. N. Kay of University of Wales, Swansea. Watsonia 20 (1995).
  8. All the Gloucestershire sites have been discovered by Mark and Clare Kitchen, the vice-county botanical recorders for Gloucestershire.
  9. Mark Hampton has conducted much surveying throughout the UK.
  10. The picture on this page is from K Tomkinson, D&E Everett (1984) Collections from the History of Worcestershire by T Nash 2nd edition 1799 - a natural history plate showing the Wyre Firest Sorbus domestica.
  11. AFLP Plant Mapping Protocol, Part number 402083, Revision B, May 1996. PE Applied Biosystems. (A Division of Perkin-Elmer)
  12. By Kausch-Blecken von Schmeling. Out of print.

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