Shropshire Botanical Society Newsletter - Spring 1999 - page 9
In 1997, as part of a course with the University of Birmingham, I undertook to draw up a checklist of Shropshire's roses using any past records available and my own findings. A need for a considerable amount of fieldwork soon became apparent as very few of the Shropshire Flora records had been confirmed by a Rosa referee. The best source of information for finding out where to look in the field was Roses of Great Britain by G.G. Graham and A.L. Primavesi. The distribution maps in this book included the majority of Shropshire's confirmed records; many of these had been collated from examination of herbarium specimens.
Tackling roses seems a very daunting task to begin with, even with the help of a good book. It was only in having such an excellent referee in Rev. Primavesi that it was at all possible (a diagnosis, occasionally a confirmation, by return of post!). It also helped that my husband had been dabbling into roses for a couple of years and had succeeded in getting quite a few interesting cuttings going in the garden.
The list provides, I hope, a definitive list of species which have been confirmed in Shropshire. Maps are given at the hectad (10km x 10km) level for all but Rosa arvensis, which is common throughout. By using only confirmed records, I have omitted many Flora records that I am sure are accurate; unfortunately I think there are some that are not.
Rosa species hybridize readily and not by a simple cross. The majority of the genetic material comes from the female parent; the hybrid therefore resembles its maternal parent more closely e.g. R. × rothschildii may closely resemble R. sherardii but have reduced hairiness, some curved prickles or caducous sepals; R. × molletorum may resemble R. mollis but have a climbing habit or a reduced orifice or longish pedicels; R. × dumalis may resemble R. caesia but have longish pedicels or a small head of stigmas. The first generation hybrids can usually be recognized (Primavesi 1993). If the first generation of hybrid is fertile it may cross again and so on, creating some complex mixtures which may be indeterminate or may fall within the range of variability of a species.
When recording a hybrid the maternal parent is written first . If the direction of the cross is indeterminate the component species are written in alphabetical order.
Of all the specimens found by myself in 1997 58% were found in hedgerow, 9% on road or trackside verge but not in hedgerow and 33% in scrub and grassland. Several species and hybrids were not found in limestone areas (Llanymynech, Dolgoch and Wenlock Edge). Rosa micrantha was only found on limestone but was absent from Wenlock Edge which proved to be disappointing as far as roses are concerned. R. canina, R. tomentosa, R.× scabriuscula, R.× rothschildii, R. × dumalis and R. × dumetorum were found on limestone and other soils.
By recording altitudes at which the 1997 specimens were found I was able to demonstrate that R. mollis and R. caesia (both northern species) and R. sherardii (a northern and western species) occur on higher land in Shropshire than all other species (R. canina and R. arvensis excluded). However in 1998 I found R. sherardii at Childs Ercall at 80m (findings between 130m and 400m in 1997). R. tomentosa and R. micrantha, both southern roses, were not found on high ground. The hybrids of the downy roses were shown to grow in a similar range of altitude to that of their downy rose parent but crosses with R. canina and the hybrid R.× dumalis had lower average altitudes than the pure downy roses or R. caesia.
There are many parts of Shropshire waiting to have their roses discovered. As shown above there does seem to be some pattern of distribution which may act as a guide for any one wishing to have a go at them.
Graham, G.G. and Primavesi, A.L. 1993 Roses of Great Britain and Ireland. BSBI, London.